Polyfluoropolyethers having pendant perfluoroalkoxy groups

ABSTRACT

Normally liquid peroxidic poly(perfluorooxyalkylene) compositions comprising a mixture of peroxidic poly(perfluorooxyalkylene) compounds, derivatives of the poly(perfluorooxyalkylene) compositions comprising a mixture of non-peroxidic polyfluoropolyether compounds, and derivatives of the polyfluoropolyether compositions comprising functional and non-functional derivatives of the polyfluoropolyether compositions are provided. Each peroxidic poly(perfluorooxyalkylene) compound comprises a backbone of randomly distributed perfluorooxyalkylene units, represented by the formulas --CF 2  O--, ##STR1## and --O--, which when bonded to and --O-- of any of the perfluorooxyalkylene units, forms a peroxy group, --O--O--, which imparts the peroxidic characteristics to the material, and backbone-pendant perfluoroalkoxy groups or perfluoroalkoxy groups substituted with one or more ether oxygen atoms, the terminal ether oxygen atoms of which are bonded to carbon atoms of the ##STR2## backbone units.

This invention relates to poly(perfluorooxyalkylene) compositions, topolyfluoropolyether compositions, to derivatives and polymers thereof,to processes for preparing same, and to articles formed therefrom.

In the perfluoropolyether art, U.S. Pat. No. 3,291,843 (Fritz et al.)discloses perfluoroalkyl perfluorovinyl ethers which have been preparedand polymerized to homopolymers and copolymerized with otherethylenically-unsaturated monomers to copolymers. These polyfluoropolymers and copolymers are solids and have a backbone structure ofcarbon-to-carbon bonds with pendant perfluoroalkoxy groups.

Later in the art, compounds were disclosed that have a backbonestructure of repeating perfluorooxyalkylene units which are prepared bythe reaction, in the presence of suitable radiation, of oxygen withtetrafluoroethylene (U.S. Pat. Nos. 3,392,097 (Gozzo et al.), 3,622,635(Gozzo et al.); and 3,715,378 (Sianesi et al.)), hexafluoropropylene(U.S. Pat. Nos. 3,451,908 (Sianesi et al.), 3,699,145 (Sianesi et al);3,721,696 (Sianesi et al.) and 3,896,167 (Sianesi et al.)), mixtures ofone or more perfluoroolefins (U.S. Pat. Nos. 3,442,942 (Sianesi et al.)and 3,450,611 (Loffelholz et al.)), or perfluorodienes (U.S. Pat. No.3,451,907 (Sianesi et al.)) or by reaction of ozone withperfluoroolefins (U.S. Pat. No. 4,003,941 (Crawford et al.)) orperfluoroolefins and perfluorocarbonyl compounds (U.S. Pat. No.3,423,364 (Kowanko)). Although these compounds have a backbone structureof repeating perfluorooxyalkylene units that can have pendant groups,these pendant groups are limited to perfluoroalkyl, perfluoroalkenyl,carbonyl fluoride, and perfluoroepoxy groups.

Fluorine-containing block copolymers having a backbone structure ofrepeating perfluorooxyalkylene units and also pendant perfluorooxygen-containing groups are described in U.S. Pat. No. 3,810,875 (Riceet al). These copolymers are prepared by contacting a diacylchloride-terminated poly(perfluoroalkylene oxide) with sodium peroxideto produce a diacyl peroxide of the poly(perfluoroalkylene oxide) whichis then used to initiate the polymerization of ethylenically-unsaturatedcompounds, including, among many ethylenically-unsaturated compounds,the completely fluorinated vinyl ethers. Block polymers prepared in thismanner, although having pendant, perfluoro, oxygen-containing groups,have these groups attached in the polymer to a backbone chain ofcarbon-to-carbon atoms that does not contain ether oxygen.

U.S. Pat. No. 3,849,504 (Mitsch) discloses perfluoropolyethers havingend group functionalities greater than two and backbone segments ofrepeating units of the formula (C_(m) F_(2m))O(C_(n) F_(2n)), (1a) and,optionally, random segments of repeating units of the formula (C_(p)F_(2p)), (1b), where m, n and p are each a positive whole number offrom, and including, 1 through 7, and further, optionally, one or morerandom branched segments of the formula ##STR3## (1c), where R is a sidechain of repeating units which have the formula (1a) or a mixed sidechain made up of random repeating units having the formulas (1a) and(1b) and R itself can have one or more branched segments as shown informula (1c). These perfluoropolyethers are prepared by irradiatingoxydi(perfluoroacyl fluorides) of the general formula FOC[(C_(m)F_(2m))O(C_(n) F_(2n))]COF where m and n are as defined above, withultraviolet light. The oxydi(perfluoroacyl fluorides) can be optionallyadmixed together with perfluorodiacyl fluorides of the general formulaFOC(C_(p) F_(2p))COF where p is as defined above.

U.S. Pat. No. 4,451,646 (Sianesi et al.) discloses high molecularweight, polymeric, perfluorinated copolyethers which have a chainstructure of --CF₂ --CF₂ --O-- and --CF₂ --O-- repeating units. Thesepolymeric perfluorinated copolyethers have molecular weights of from22,000 to 75,000, a ratio of --CF₂ --CF₂ --O-- units to --CF₂ --O--units of 0.2 to 25, and an average sum of repeating units along thechain of 220 to 624. These polymeric, perfluorinated copolyethers areprepared by reacting molecular oxygen with tetrafluoroethylene dissolvedin a fluorinated or chlorofluorinated solvent under specified conditionsof tetrafluoroethylene/oxygen ratio, temperature, pressure, and U.V.radiation levels.

U.S. Pat. No. 4,500,739 (Caporiccio et al.) disclosesperfluoropolyethers having in the polymeric chain at least threedifferent alkylene units linked to each other through etheric bridgesand arranged by a random distribution along the polymer chain. Two ofthe units, consisting of --CF₂ -- and --C₂ F₄ --, are those resultingfrom the photo-oxidation of C₂ F₄ and pre-existed in the structure ofthe peroxidic precursor, while the third alkylene unit consists of threeor more carbon atoms and is introduced into the chain by reacting afluoroolefin with the peroxidic precursor. The fluoroolefins, such ashexafluoropropene, 1-hydropentafluoropropene-1,2-hydropentafluoropropene-1, perfluoromethylvinylether,perfluoropropylvinylether,4-trifluoromethyl-3,6-dioxaperfluoroheptene-1,4,6-dioxaperfluoroheptene-1, cycloperfluorobutene, perfluorobutadiene,and trifluorobromoethylene, are reacted with the radicals of theperfluoroalkoxidic type, generated by the fission of the peroxidic--O--O-- bond, or they react with the radicals of the perfluoroalkylenictype coming from the immediate metathesis of perfluoroalkoxidic radicalsthrough the β-scission mechanism. This insertion of the fluoroolefinforms chain segments having three or four caternary carbon atoms.

Polyfunctional poly(perfluoroalkylene oxides), their preparation andtheir use in the preparation of polymers are disclosed in U.S. Pat. No.3,810,874 (Mitsch et al.). The compounds described are linear,polyfunctional-terminated poly(perfluoroalkylene oxide) compounds of theformula

    A--CF.sub.2 O--CF.sub.2 CF.sub.2 O--.sub.m --CF.sub.2 O--.sub.n CF.sub.2 --A'

where A and A' are terminal reactive radicals bonded to a connecting--CF₂ -- group (as shown) and m and n designate the number of randomlydistributed perfluoroethyleneoxy and perfluoromethyleneoxy backbonerepeating subunits, respectively. The ratio m/n is 0.2/1 to 5/1 and thecompounds have a number average molecular weight in the range of 500 to20,000 or higher, preferably 800 to 15,000. Mitsch et al. disclose thatthe polymers that can be prepared from the polyfunctional-terminatedpoly(perfluoroalkylene oxides) have unexpectedly low glass transitiontemperatures, are flexible at low temperature, and possess solventresistance and good hydrolytic, thermal, and oxidative stability.

This invention provides, in one aspect, normally liquid peroxidicpoly(perfluorooxyalkylene) composition comprising a mixture of peroxidicpoly(perfluorooxyalkylene) compounds, each compound comprising, orconsisting essentially of, a backbone, or chain, of randomlydistributed, perfluorooxyalkylene units represented by the formulas--CF₂ O--, ##STR4## the depicted carbon and oxygen atoms of which arecaternary backbone atoms, and --O--, which, when bonded to an --O-- ofany of the perfluorooxyalkylene units, forms a peroxy group, --O--O--,which imparts the peroxidic characteristics to the composition, andbackbone-pendant perfluoroalkoxy groups or perfluoroalkoxy groupssubstituted with one or more ether oxygen atoms, the terminal etheroxygen atoms of which are bonded to carbon atoms of the ##STR5##backbone units, and functional or non-functional groups, e.g., --COF or--CF₃, terminating said backbone, which backbone can have a wide rangeof number average molecular weights, e.g., 1000 to 1,000,000, or more,with the terminal groups having effect on composition properties athigher molecular weights. In another aspect, this invention providesderivatives of the poly(perfluorooxyalkylene) compositions comprising amixture of non-peroxidic polyfluoropolyether compounds. In a furtheraspect, this invention provides functional and non-functionalderivatives of the non-peroxidic polyfluoropolyether compositions. Inanother aspect, this invention provides polymers of the functionalpolyfluoropolyether compositions. In a further aspect, this inventionprovides a process for preparing the peroxidicpoly(perfluorooxyalkylene) in compositions involving photooxidation of amixture of perfluoroolefins and perfluoro(alkyl vinyl) ethers in thepresence of oxygen. In a still further aspect, this invention providesarticles produced from the functional polyfluoropolyether compositions.

As used herein in describing our invention, the term "perfluoroalkoxy"is a term generic to unsubstituted perfluoroalkoxy groups having asingle terminal oxygen atom, such as CF₃ O--, CF₃ CF₂ O--, C₆ F₁₁ O--,and the like, and perfluoroalkoxy groups substituted with one or morefurther ether oxygen atoms, such as CF₃ O--CF₂ O--, CF₃ CF₂ O--CF₂ CF₂O--CF₂ CF₂ O--, and the like, said perfluoroalkoxy group being acyclicor cyclic and having, for example, 1-28 carbon atoms and 1-7 etheroxygen atoms.

There will now be described various classes of polyfluoropolyethercompositions of this invention. In these descriptions, formulas forbackbone structures or chains are set forth, those backbone structuresor chains (enclosed by braces) comprising various structural units,e.g., --CF₂ O--, randomly distributed within the chain (rather than inthe order depicted in the formulas for purposes of brevity).

A class of the polyfluoropolyether compositions of this inventioncomprises polyfluoropolyethers which have a backbone or linear chainstructure comprising, or consisting essentially of, and represented bythe formula ##STR6## where each R¹ is independently a fluorine or aperfluoroalkyl group selected from linear groups, e.g., having 1 to 10carbon atoms, branched groups, e.g., having 3 to 10 carbon atoms, andcyclic groups, e.g., having 3 to 6 carbon atoms, R¹ preferably being --For --CF₃ ;

each OR² is independently a perfluoroalkoxy group wherein R² is aperfluoroalkyl group or a perfluoroalkyl group substituted with one ormore ether oxygen atoms, which can be independently selected from unitshaving the structure --R³ O--_(f) R⁴, in which each R³ is independentlyselected from --CF₂ --, --CF₂ CF₂ -- and ##STR7## and R⁴ is aperfluoroalkyl group selected from linear groups, e.g., having 1 to 10carbon atoms, branched groups, e.g., having 3 to 10 carbon atoms, andcyclic groups, e.g., having 3 to 6 carbon atoms, and f is zero or anumber having a value of 1 to 6, R₄ preferably being --CF₃, --C₂ F₅,--C₃ F₇, or --C₄ F₉ ;

w is a number representing the average number of --CF₂ O-- unitsrandomly distributed within the chain and has a value of 1 or greater,e.g., up to about 10,000, w preferably being 1 to about 5000 when R¹ is--F and 1 to about 50 when R¹ is --CF₃ ;

x is a number representing the average number of ##STR8## units randomlydistributed within the chain and has a value of 1 or greater, e.g., upto about 10,000, x preferably being 1 to about 6000 when R¹ is --F andabout 5 to 50 when R¹ is --CF₃ ;

y and y' are each a number representing the average number of ##STR9##units, respectively, randomly distributed within the chain, the sum of yand y' having a value of 1 or greater, e.g., up to about 800, the sumpreferably being 1 to about 600 when R¹ is --F and 1 to about 50 when R¹is --CF₃, and the ratio y/y' being 0 to 5;

z is a number representing the average number of oxygen atoms, --O--,randomly distributed within the chain which when bonded to an --O-- ofthe --CF₂ O--, ##STR10## forms a peroxy group, --O--O--, and has a valueof 0, in which case the polyfluoropolyethers are non-peroxidic, orgreater, e.g., up to about 5000, preferably up to about 1500 when R¹ is--F and up to about 15 when R¹ is --CF₃ ;

the ratio w/x is 5 or less, the ratio preferably being about 0.5 to 5when R¹ is --F and about 0.05 to 0.5 when R¹ is --CF₃ ;

the ratio (y+y')/(w+x) is 0.01 to 1.5, preferably 0.05 to 1.5, the ratiopreferably being about 0.05 to 1 when R¹ is F, and about 0.1 to 1.0 whenR¹ is CF₃ ;

the ratio z/(w+x+y+y') is 0 to 1, the ratio preferably being 0 to about0.5 when R¹ is --F and 0 to about 0.1 when R¹ is --CF₃ ; and

the number average molecular weight of the polyfluoropolyethers ispreferably from about 650 to 1,000,000 or more.

A class of the polyfluoropolyether compositions of the inventioncomprise polyfluoropolyethers having the above-described polyether chainand can be represented by the formula ##STR11## where R¹, R², w, x, y,y' and z are as defined above,

when z is zero, G and J are independently selected from C_(j) F_(2j) Xin which X is hydrogen or halogen, e.g., --F or --Cl, and when X ishydrogen then j is 1 or 2, and when X is halogen then j is an integer of1 to 5, or G and J are terminal functional groups which can enter intoan addition or condensation reaction to form a homopolymer or copolymer,and

when z is 1 or greater, e.g., up to about 5000, or when z is zero, G isselected from ##STR12## and J is selected from ##STR13## where a is aninteger of 1 to 5, and the number average molecular weight of thepolyfluoropolyethers can be in the range of from about 650 to 1,000,000or more, preferably in the range of about 1000 to 1,000,000 when R¹ is--F and about 1000 to 6000 when R¹ is --CF₃.

A class of the peroxidic poly(perfluorooxyalkylene) compositions of thisinvention comprise peroxidic poly(perfluorooxyalkylenes) which is asubclass within the scope of formula II and can be represented by theformula ##STR14## wherein R¹ and R² are as described above;

Q is selected from --COF, --CF₂ COF, --CF₂ COCF₃, --CF₂ C(OH)₂ CF₃,##STR15## and --CF₂ COOH; W is a terminal group selected from Q, C_(a)F_(2a+1), and C_(a) F_(2a) Cl where a is an integer up to 5;

b is a number representing the average number of --CF₂ O-- unitsrandomly distributed within the chain and has a value of 1 or greater,e.g., up to about 10,000, b preferably being 1 to about 5000 when R¹ is--F and 1 to about 50 when R¹ is --CF₃ ;

c is a number representing the average number of ##STR16## unitsrandomly distributed within the chain and has a value of 1 or greater,e.g., up to about 10,000, c preferably being 1 to about 6000 when R¹ is--F and about 5 to 50 when R¹ is --CF₃ ;

d and d' are each a number representing the average number of ##STR17##units, respectively, randomly distributed within the chain, the sum of dand d' has a value of 1 or greater, e.g., up to about 800, the sumpreferably being 1 to about 600 when R¹ is --F and 1 to about 50 when R¹is --CF₃, and the ratio d/d' is 0 to 5;

e is a number representing the average number of --O-- units randomlydistributed within the chain and has a value of 1 or greater, e.g., upto about 5000, e preferably being 1 to about 1500 when R¹ is --F and 1to about 15 when R¹ is --CF₃ ;

the ratio b/c is less than 5, preferably 0.5 to 5 when R¹ is --F andless than 0.5 when R¹ is --CF₃ ;

the ratio (d+d')/(b+c) is 0.01 to 1.5, preferably 0.05 to 1.5, the ratiopreferably being about 0.05 to 1 when R¹ is --F and about 0.1 to 1 whenR¹ is --CF₃ ;

the ratio e/(b+c+d+d') is 0.0001 to 1, the ratio preferably being 0.001to 0.5 when R¹ is --F and 0.03 to 0.1 when R¹ is --CF₃ ; and

the number average molecular weight of the poly(perfluorooxyalkylenes)can be from about 650 to 1,000,000 or more, preferably 1000 to 1,000,000when R¹ is --F and 1000 to 6000 when R¹ is --CF₃.

The peroxidic poly(perfluorooxyalkylene) compositions are useful ascrosslinking agents for elastomeric polymers, such as fluorinatedpolymers and copolymers, for example, copolymers of vinylidene fluorideand hexafluoropropylene, as initiators for free-radical polymerization,and as precursors for forming non-peroxidic polyfluoropolyethers of thisinvention.

A class of the non-peroxidic polyfluoropolyether compositions of thisinvention comprise non-peroxidic polyfluoropolyethers which is asubclass within the scope of formula II and can be represented by theformula ##STR18## wherein R¹ and R² are as defined for formula I;

each Z is independently a terminal group which is a functional, orpolymerizable, group Y, which is or contains a functional moiety whichcan enter into an addition or condensation reaction to form ahomopolymer or copolymer, or Z is a non-functional, or inert, groupC_(j) F_(2j) X in which X is hydrogen or halogen, e.g., --F or --Cl, andwhen X is hydrogen then j is 1 or 2, and when X is halogen then j is aninteger of 1 to 5;

g is a number representing the average number of --CF₂ O-- unitsrandomly distributed within the chain and has a value of 1 or greater,e.g., up to about 2000, g preferably being 1 to about 1000 when R¹ is--F and 1 to about 25 when R¹ is --CF₃ ;

h is a number representing the average number of ##STR19## unitsrandomly distributed within the chain and has a value of 1 or greater,e.g., up to about 2000, h preferably being 1 to about 1000 when R¹ is--F and about 5 to 50 when R¹ is --CF₃ ;

i and i' are each a number representing the average number of ##STR20##units, respectively, randomly distributed within the chain, the sum of iand i' has a value of 1 or greater, e.g., up to about 50, the sumpreferably being 1 to about 30 when R¹ is --F and 1 to about 25 when R¹is --CF₃, and the ratio i/i' is 0 to 5;

the ratio g/h is less than 5, preferably 0.5 to 5 when R¹ is --F andless than 0.5 when R¹ is --CF₃ ;

the ratio (i+i')/(g+h) is 0.01 to 1.5, preferably 0.05 to 1.5, the ratiopreferably being 0.05 to 1 when R¹ is --F and 0.1 to 1 when R¹ is --CF₃; and

the number average molecular weight of the polyfluoropolyether can beabout 650 to 20,000, preferably about 1000 to 10,000 when R¹ is --F and1000 to 6000 when R¹ is --CF₃.

A preferred subclass of the non-peroxidic polyfluoropolyethercompositions of the invention are inert liquids comprisingpolyfluoropolyethers represented by the formula ##STR21## where R¹, R²,g, h, i, i', and --C_(j) F_(2j) X are as defined for formula IV.

The inert liquids, which include products having boiling ranges fromabout 140° C. at one atmosphere to more than 350° C. at 0.1 torr andviscosities ranging from less than one centistoke to several thousandcentistokes at room temperature, are useful in various applications.Lower boiling fractions can be used as solvents, dielectric media,hydraulic fluids, and heat transfer fluids. The higher boiling fractionsand distillation residues can be used for lubricants, especially inapplications requiring both low viscosity and inertness to harshconditions, such as those found in semiconductor processing equipment.

A further preferred subclass of the non-peroxidic polyfluoropolyethercompositions of the invention comprise mono- or di-functionalpolyfluoropolyethers represented by the formula ##STR22## where R² and Yare as defined above;

R⁶ is preferably Y as defined for formula IV, but can be aperfluoroalkyl or haloperfluoroalkyl group having, e.g., 1 to 5 carbonatoms, and preferably selected from --CF₃, --CF₂ CF₃, --CF₂ Cl and --CF₂CF₂ Cl;

k is a number representing the average number of --CF₂ O-- unitsrandomly distributed within the chain and has a value of 1 to about 200;

l is a number representing the average number of --CF₂ CF₂ O-- unitsrandomly distributed within the chain and has a value of 1 to about 200;

p and p' are each a number representing the average number of ##STR23##units, respectively, randomly distributed within the chain, the sum of pand p' has a value of 1 to about 50, and the ratio p/p' is 0 to 5;

the ratio k/l is less than 5;

the ratio (p+p')/(k+l) is 0.01 to 1.5, preferably 0.05 to 1; and

the number average molecular weight of the polyfluoropolyether can befrom about 650 to 20,000, preferably about 1000 to 10,000.

Another preferred subclass of the non-peroxidic polyfluoropolyethercompositions of the invention comprise functional polyfluoropolyethersrepresented by the average formula ##STR24## where R² and Y are asdefined above;

R⁷ is Y or a perfluoroalkyl or haloperfluoroalkyl group having, e.g.,one to five carbon atoms, with R⁷ preferably being selected from --CF₃,--CF₂ CF₃, and --CF₂ CF(CF₃)₂ ;

q is a number representing the average number of --CF₂ O-- unitsrandomly distributed within the chain and has a value of 1 up to about50, preferably 1 to 15;

r is a number representing the average number of ##STR25## unitsrandomly distributed within the chain and has a value of 5 up to about50, preferably 5 to 30;

s and s' are each a number representing the average number of ##STR26##units, respectively, randomly distributed within the chain, the sum of sand s' has a value of 1 up to about 40, preferably 1 to 15, and theratio s/s' is 0 to 5;

the ratio q/r is 0.01 to 1, preferably 0.05 to 0.5; the ratio(s+s')/(q+r) is 0.01 to 1, preferably 0.05 to 1, more preferably 0.05 to0.5; and

the number average molecular weight of the polyfluoropolyether is from650 to 10,000, preferably 1000 to 6000.

The functional group-terminated polyfluoropolyethers of formulas VI andVII are useful as lubricants, viscosity index additives forperhalogenated lubricants, hydraulic fluids, water and oil repellents,surface active agents, anti-corrosion agents, mold release agents,release agents for pressure-sensitive adhesives, flotation agents,plasticizers for fluorinated plastics, and prepolymers which can bepolymerized to form molded articles, such as hoses and gaskets which arechemically resistant and flexible at low temperatures, and as aconstituent of ophthalmic lenses. Particularly useful functionalterminal groups include, for example, hydroxyl, ester, acrylate andmethacrylate, and substituted silane.

The structures of the polyfluoropolyethers having pendantperfluoroalkoxy groups, --OR², of this invention can be determined by ¹⁹F nuclear magnetic resonance (NMR) analysis. The backbone unit ratioscan be calculated from ratios of the integrated peak intensities of theNMR spectrum. The number average molecular weights can be calculatedfrom end group analysis.

Although the compounds of formula IV, VI, and VII are shown as beingmonofunctional or difunctional, the actual products prepared aregenerally mixtures of monofunctional, difunctional, and inert compounds.Products called "monofunctional" herein generally contain less than 25weight percent each of difunctional and inert compounds. Products called"difunctional" herein preferably contain less than 20 weight percent,more preferably less than 10 weight percent total monofunctional andinert compounds.

The compositions of the invention as prepared generally are mixtures ofpolyfluoropolyethers having --CF₂ O--, ##STR27## and, optionally, --O--backbone units, but may contain small amounts, i.e., less than 10 molepercent, of other backbone units, such as --CF(CF₃)O--, --CF₂)_(n) O--where n is greater than 2, and --CF₂ CF(CF₃)CF₂ O--, the small amountsof these other units not affecting the general properties of thecompositions of the invention. The compositions may also contain a smallamount of molecules having no ##STR28## thus resulting in compositionswhere the average number of ##STR29## backbone units per molecule isless than one.

The invention also provides various processes for the preparation ofpolyfluoropolyether compositions. The process for preparing thecompositions comprising the peroxidic carbonylfluoride-terminatedpolyfluoropolyether compositions comprises photooxidizing a mixture ofperfluoroolefin and perfluoro(alkyl vinyl) ether by the steps of

(a) introducing into a reaction vessel, optionally containing an inerthalocarbon solvent, reactants comprising

(i) one or more perfluoroolefins,

(ii) one or more perfluoro(alkyl vinyl) ethers, and

(iii) oxygen,

(b) exposing the resulting reaction mixture to actinic radiation to forma peroxidic poly(perfluorooxyalkylene) composition comprising peroxidicpoly(perfluorooxyalkylenes) represented by Formula III.

Generally, the reaction can be carried out at a temperature of fromabout -100° C . to 25° C. and at a pressure of 0.5 to 10 atmospheres.The preferred actinic radiation is ultraviolet radiation having awavelength distribution between about 1800 and 3000 A.

The peroxidic poly(perfluorooxyalkylene) reaction product can then besubjected to partial or complete deperoxidation, preferably by thermaland/or ultraviolet radiation treatment as described in U.S. Pat. Nos.3,442,942 and 3,715,378 (Sianesi et al.), which patents are incorporatedherein by reference for a description of said treatment. The resultingproduct is either a reduced peroxidic product such as that comprisingcompounds of Formula III or a product comprising completely deperoxidedpolyfluoropolyether such as that represented by the formula ##STR30##wherein Q and W are as defined above for formula III;

R¹, and R² are the same as defined above;

t and u are numbers independently having a value of 1 to about 1000; theratio t/u is less than about 5; and

v and v' are each a number representing the average number of ##STR31##respectively, randomly distributed within the chain, the sum of v and v'has a value of 1 or greater, e.g., up to about 600, and the ratio v/v'is 0 to 5;

the ratio of (v+v')/(t+u) is 0.01 to 1.5, preferably 0.05 to 1.5; and

the number average molecular weight can be in the range of from about650 to 1,000,000.

The functional group-terminated polyfluoropolyether compositionscomprising the polyfluoropolyethers, such as represented by formulas VIand VII can be formed by reduction of the peroxidic compositioncomprising the peroxidic poly(perfluorooxyalkylenes) such as representedby Formula III, the reduction of the modified (reduced peroxide)polyfluoropolyether composition comprising the polyfluoropolyether suchas represented by Formula III, or the reduction of the deperoxidizedproduct of Formula VIII to form compositions comprising ester- oralcohol-terminated polyfluoropolyethers such as represented by FormulaVI or VII using known chemical techniques.

To produce the polyfluoropolyether compositions comprising thepolyfluoropolyethers represented by Formula VI, the preferred method isto react the reduced peroxidic composition comprising thepoly(perfluorooxyalkylenes) represented by Formula III with hydriodicacid and methanol to form polyfluoropolyether compositions comprisingdifunctional methyl ester-terminated polyfluoropolyethers represented byFormula VI. These ester end-groups can then be converted to otherfunctional end-groups as disclosed in U.S. Pat. Nos. 3,810,874,4,085,137, and 4,094,911 (Mitsch et al.), which patents are incorporatedherein by reference for a description of said conversion.

To produce the compositions comprising the polyfluoropolyethersrepresented by Formula VII, the preferred method is to completelydeperoxidize the peroxidic composition comprising thepoly(perfluorooxyalkylenes) represented by Formula III to form thenonperoxidic composition comprising the polyfluoropolyether representedby Formula VIII. This latter composition is then treated with a reducingagent such as sodium borohydride to form an alcohol. The alcohol canthen be derivatized by procedures described in U.S. Pat. No. 4,094,911to yield various derivatives.

The polyfluoropolyether compositions comprising the polyfluoropolyethersrepresented by Formula V are preferably prepared by subjecting theperoxidic composition comprising the poly(perfluorooxyalkylenes)represented by Formula III or the deperoxidized composition comprisingthe polyfluoropolyether represented by Formula VIII, to either a thermaltreatment in the presence of elemental fluorine, a thermal treatment inthe presence of an alkali metal hydroxide, or a thermal treatment in thepresence of an alkali metal hydroxide followed by chlorination orfluorination. When the thermal treatment in the presence of an alkalimetal hydroxide is used alone an inert fluid of Formula V is obtained inwhich X is hydrogen and, when this thermal treatment is followed bychlorination or fluorination, an inert fluid of Formula V is obtained inwhich X is chlorine and fluorine, or fluorine only, respectively.

Examples of perfluoroolefins that, either alone or in admixture with oneanother, can be used as reactants in the process of the inventioninclude any perfluoroolefin having α, β-ethylenic unsaturation, such astetrafluoroethylene, hexafluoropropylene, octafluorobutene-1,decafluoropentene-1, and perfluoroheptene-1. Generally, any of theperfluoroolefins having 2 to about 12 carbon atoms and which are linearor branched, and which can contain cyclic substituents having 3 to 6carbon atoms can be used. Preferably, the reactant istetrafluoroethylene and/or hexafluoropropylene.

The perfluoro(alkyl vinyl) ether used to make the compositions of theinvention can be represented by the general formula

    F.sub.2 C═CFOR.sup.2

wherein R² is as defined for Formula I. Examples of usefulperfluoro(alkyl vinyl) ethers include the following: ##STR32## Theperfluoro(alkyl vinyl) ethers are well known and are prepared byreactions known in the art. (See, for example, U.S. Pat. No. 3,114,778.)

In the first step of the photooxidation process of the invention, amixture of perfluoroolefin(s) and perfluoro(alkyl vinyl) ether(s) isphotooxidized in a batchwise or continuous process. In the batchwiseprocess, the reactor can be equipped with a cooling jacket, a quartzimmersion well containing a source of actinic radiation, preferablyultraviolet radiation, such as is emitted by a mercury vapor lamp, athermocouple, means for introducing a gas below the surface of a liquidcontained in the reactor, and a reflux condenser that is cooled to andmaintained at a temperature, for example, of from about -100° C. toabout 25° C., preferably between about -75° C. and -25° C. A mixture ofthe perfluorinated reactants, for example, one part by weight of one ormore perfluoroolefins and 0.01 to 100 parts by weight, preferably 0.1 to0.5 parts by weight, of one or more perfluoro(alkyl vinyl) ethers andoptionally up to about 100 parts by weight of one or more solvents,preferably a halocarbon solvent such as dichlorodifluoromethane,hexafluoroethane, or trichlorotrifluoroethane, can be introduced intothe reactor either all at the beginning of the reaction or one or moreof the perfluoroolefins and perfluoro(alkyl vinyl) ethers are addedcontinuously during the course of the reaction period. Ultravioletradiation is activated and a flow of a molecular oxygen-containing gas,e.g., oxygen, oxygen diluted with an inert gas such as nitrogen orargon, or air is initiated and continued at a rate sufficient tomaintain a steady state saturation of the mixture with oxygen. Whentetrafluoroethylene is the olefin being used in the reaction, it ispreferable that it be added continuously, and that the molar ratio ofoxygen flow to tetrafluoroethylene flow be greater than about 2.0 toavoid formation of poly(tetrafluoroethylene). Perfluoroolefins,perfluoro(alkyl vinyl) ethers, and solvents that are entrained ineffluent gases are returned to the reactor by the reflux condenser. Thereaction mixture is kept at a desired temperature, for example, betweenabout -100° C. and 25° C., preferably between -50° C. and -30° C., andpressure maintained, for example, at about 0.5 to 10 atmospheres,preferably about 1 atmosphere. The reaction is allowed to proceed for atime from less than one hour to 24 hours or longer. At the end of thereaction period, volatile materials are removed to recover the reactionproduct as a fluid containing the peroxidic poly(perfluorooxyalkylenes)represented by Formula III. Generally, the lower the reactiontemperature, the higher the number average molecular weight of theproduct as determined by ¹⁹ F nuclear magnetic resonance (NMR)spectroscopy.

In the continuous process, the reactor can be equipped as in thebatchwise process. The continuous process also has a means ofcontinuously withdrawing a portion of the reaction mixture andsubjecting it to distillation. The reactor is maintained, for example,at a temperature from about -100° C. to about 25° C., preferably fromabout -75° C. to about -25° C., and at a pressure, for example, betweenabout 0.5 to 10.0 atmospheres, preferably at atmospheric pressure.

The continuous process is started as in the batchwise process. A portionof the perfluoroolefins, perfluoro(alkyl vinyl) ethers, and optionalsolvents may be charged into the reactor at the beginning as in thebatchwise process, with the remainder being added continuously over thecourse of the reaction period. Either immediately upon starting, or upto 10 hours later, a portion of the reaction mixture is continuouslywithdrawn from the reactor. This mixture is distilled, the nonvolatileproduct containing the peroxidic poly(perfluorooxyalkylenes) of FormulaIII is collected, and the volatile components, i.e., unreacted monomersand optional solvents, can be returned to the reactor. Additionalamounts of monomers and solvents can be added continuously as thereaction proceeds in order to replace materials lost by reaction orwhich escape through the reflux condenser. The rates of makeup feed andproduct takeoff are such that the residence time of perfluoroolefins inthe presence of ultraviolet radiation is between about 15 minutes and 8hours.

The photooxidation composition comprising thepoly(perfluorooxyalkylenes) represented by Formula III may be subjectedto partial or complete deperoxidation, for example by thermal and/orultraviolet radiation treatment. This results in either a modifiedproduct with reduced peroxide content which can still be described as acomposition comprising poly(perfluorooxyalkylenes) represented byFormula III, or a completely deperoxidized composition comprising thepolyfluoropolyether represented by Formula VIII. When using thermaltreatment to modify the peroxidic composition comprising thepoly(perfluorooxyalkylenes) represented by Formula III, it is necessaryto heat the material in the exclusion of oxygen at a rate of less than1° C. per minute, preferably less than 0.5° C. per minute. Thetemperature of the material is held at, for example, from 150° to 200°C. for a length of time from one hour up to 60 hours or longer. Becauseof the danger of explosion, it is desirable that the heating take placein a safety bunker.

The peroxide content of the photooxidation products can also be reducedby exposure to ultraviolet radiation in the absence of oxygen. Thereaction can be carried out neat or in solution, for example, in up toabout twenty parts by weight of an inert solvent per part ofphotooxidation product, preferably one to 15 parts by weight, and at atemperature, for example, of from zero to 50° C., preferably 25° to 35°C. Ultraviolet radiation having a wavelength from about 1800 to 3000 Åcan be used. The resulting products comprise either modifiedpolyperoxides having reduced peroxide content as represented by FormulaIII, or comprise completely deperoxidized materials represented byFormula VIII.

Compositions comprising functional group-terminated polyfluoropolyethersrepresented by Formulas VI and VII can be formed by reduction of thephotooxidation product comprising the peroxidicpoly(perfluorooxyalkylenes) represented by Formula III, the modifiedperoxidic composition comprising the peroxidicpoly(perfluorooxyalkylenes) represented by Formula III, or thedeperoxidized compositions comprising the polyfluoropolyethersrepresented by Formula VIII to form polyfluoropolyether compositionscomprising the ester- or alcohol-terminated polyfluoropolyethersrepresented by Formula VI or VII. The ester and alcohol end groups canbe converted into other end groups represented in Formulas VI and VIIusing classical techniques well-known to those skilled in the art.

The polyfluoropolyether compositions comprising polyfluoropolyethersrepresented by Formula VI are preferably prepared by reacting modified(reduced peroxide) compositions comprising poly(perfluorooxyalkylenes)represented by Formula III with hydriodic acid and methanol to formprimarily difunctional methyl ester-terminated polyfluoropolyethers.This reaction is preferably carried out in a solvent such as Freon™113,refluxing the mixture for 10 to 15 hours. The solution is washed firstwith sulfur dioxide saturated water to remove iodine, then withdeionized water. The solvent is removed by distillation. Thedifunctional esters can then be converted to various functionalgroup-terminated polyfluoropolyethers using classical methods such astaught in U.S. Pat. Nos. 3,810,874 and 4,094,911.

The polyfluoropolyether compositions comprising the polyfluoropolyethersrepresented by Formula VII are preferable prepared by reacting thecomposition comprising deperoxidized polyfluoropolyether represented byFormula VIII with sodium borohydride and zinc chloride to form primarilymonofunctional hydroxy-terminated products. The hydroxy-terminatedmaterial can then be converted to various functional group-teminatedpolyfluoropolyethers using methods such as those taught in U.S. Pat.Nos. 3,810,874 and 4,094,911.

Preferably, Y in Formulas IV, VI, and VII has its functional moietyattached to the poly(perfluorooxyalkylene) backbone or chain via aconnecting divalent group such as ##STR33## Examples of the functionalmoieties include --OH, --SH, --NHR⁹, --COOR⁸, --SiR⁸.sub.α R¹⁰ _(3-'),--CN, --NCO, ##STR34## --N═C, --I, --CHO, --CH(OCH₃)₂, --SO₂ Cl,--C(OCH₃)═NH, --C(NH₂)═NH, and the like, wherein R⁸ is lower alkyl C₁-C₈ or phenyl, R⁹ is hydrogen or R⁸, R¹⁰ is a hydrolyzable group such ashalogen, an alkoxy or an acyloxy group having 1 to 6 carbon atoms, α isan integer of 1 to 3, R¹¹ and R¹² are independently hydrogen or loweralkyl of 1 to 4 carbon atoms or R¹¹ and R¹² together are alkylene andwith carbons to which they are attached form a carbocyclic ring of 5 or6 carbon atoms.

Preferred connecting groups in Y for the polyfluoropolyethersrepresented by Formula VI includes --CF₂ CH₂ -- and for thepolyfluoropolyethers represented by Formula VII includes ##STR35## and--CF₂ CH₂ -- which connect functional moieties preferably selected fromα,β-ethylenically-unsaturated alkyl, 1,2-epoxy, isocyanato, andhydrolyzable silyl-terminated groups. Examples of such functionalmoieties are: ##STR36##

An additional preferred connecting group for the polyfluoropolyethersrepresented by Formula VI is ##STR37## which connects functional groupspreferably selected from α,β-ethylenically-unsaturated alkyl, 1,2-epoxy,hydroxy, and hydrolyzable silyl groups, such as --OCH═CH₂, ##STR38##--OCH₂ CH═CH₂, --NHCH₂ CH₂ OH, ##STR39## --N(CH₂ CH₂ OH)₂, --NHCH₂CH═CH₂, --NH(CH₂)₃ Si(OCH₃)₃, --N(CH₂ CH═CH₂)₂, --OCH₂ CH(OH)CH₂ O(CH₂)₃Si(OCH₃)₃.

Compositions comprising the compounds represented by Formulas IV, VI,and VII can be prepared by either of the following two processes.

(1) Where the connecting group in Y of Formula VI is ##STR40## thecompounds are prepared from carbonyl fluoride-terminatedperfluoropolyethers, or the corresponding carboxylic acids or esters, byreaction with a hydroxy or a primary or secondary amino reactant alsohaving a functional moiety that can enter into an addition orcondensation reaction to form a polymer. Examples of such reactants are##STR41## HOCH₂ CH═CH₂, HN(CH₂ CH═CH₂)₂, H₂ N(CH₂)₃ Si(OCH₃)₃, HOCH₂ CH₂NHCH₂ CH₂ OH, HOCH₂ CH₂ NH₂.

(2) Where the connecting group in Y of formula VI is --CF₂ CH₂ -- and inFormula VII is --CF₂ CH₂ --, ##STR42## the compounds are prepared byfirst reducing the terminal carbonyl fluoride groups to thehydroxy-terminated polyfluoropolyether represented by the formula##STR43## wherein g, h, i, i', R¹, and R² are as defined for Formula IV,D is a connecting group selected from --CF₂ CH₂ --, ##STR44## and R¹³ isselected from --CF₂ CH₂ OH, ##STR45## --CF₃, --CF₂ CF₃, --CF₂ CF(CF₃)₂,--CF₂ Cl, and --CF₂ CF₂ Cl.

The hydroxy-terminated polyfluoropolyether of Formula IX is thenconverted to other functional terminal products by reaction with apolyfunctional reactant that has a functional moiety reactive with analcohol to form a covalent bond between the reactant and the oxygen ofthe alcohol and has another functional moiety that can enter into acondensation or addition reaction to form a polymer. Examples of suchreactants are ##STR46##

Illustrative of the functional group-terminated polyfluoropolyethercompositions of the invention are those represented by the formula##STR47## where R¹ and R² are as defined for formula I; Y, g, h, i, andi are as defined for Formula IV; and R¹⁴ is Y or a perfluoroalkyl orhaloperfluoroalkyl group having one to five carbon atoms.

Various functional terminal groups, Y, and the polyfunctional organicreactants which react with the hydroxyl-, ester-, acid fluoride-, orcarboxylic acid-terminated polyfluoropolyether precursor material toform the products represented by Formula X are set forth in Table I.

                                      TABLE I                                     __________________________________________________________________________    Y                              REACTANT                                       __________________________________________________________________________     ##STR48##                                                                                                    ##STR49##                                      ##STR50##                                                                                                    ##STR51##                                      ##STR52##                                                                                                    ##STR53##                                      ##STR54##                                                                                                    ##STR55##                                      ##STR56##                                                                                                    ##STR57##                                      ##STR58##                                                                                                    ##STR59##                                      ##STR60##                                                                                                    ##STR61##                                      ##STR62##                                                                                                    ##STR63##                                      ##STR64##                                                                                                    ##STR65##                                      ##STR66##                                                                                                    ##STR67##                                      ##STR68##                                                                                                    ##STR69##                                      ##STR70##                     OCNCH.sub.2 CH.sub.2 CH.sub.2 Si(OCH.sub.3)                                   .sub.3                                          ##STR71##                                                                                                    ##STR72##                                     CF.sub.2 CH.sub.2 OCH.sub.2 CHCH.sub.2                                                                        ##STR73##                                      ##STR74##                     H.sub.2 NCH.sub.2 CH.sub.2 CH.sub.2                                           Si(OCH.sub.2 CH.sub.3).sub.3                    ##STR75##                     H.sub.2 NCH.sub.2 CHCH.sub.2                    ##STR76##                     H.sub.2 NCH.sub.2 CH.sub.2 CH.sub.2 OH          ##STR77##                                                                                                    ##STR78##                                      ##STR79##                     NH.sub.3                                        ##STR80##                     H.sub.2 NCH.sub.2 CH.sub.2 NH.sub.2             ##STR81##                     H.sub.2 NCH.sub.2 CH.sub.2 CH.sub.2 COOH        ##STR82##                     HN(CH.sub.2 CH.sub.2 OH).sub.2                  ##STR83##                                                                                                    ##STR84##                                      ##STR85##                                                                                                    ##STR86##                                      ##STR87##                     HN(CH.sub.2 CHCH.sub.2).sub.2                  CF.sub.2 CONHCH.sub.2 CHCH.sub.2                                                                             H.sub.2 NCH.sub.2 CHCH.sub.2                   CF.sub.2 CON(CH.sub.3)CH.sub.2 CH.sub.2 OH                                                                   HN(CH.sub.3)CH.sub.2 CH.sub.2 OH               CF.sub.2 CONHCH.sub.2 CH.sub.2 SH                                                                            H.sub.2 NCH.sub.2 CH.sub.2 SH                  CF.sub.2 CONH(CH.sub.2).sub.3 Si(OCH.sub.3).sub.3                                                            H.sub.2 N(CH.sub.2).sub.3 Si(OCH.sub.3).sub                                   .3                                              ##STR88##                                                                                                    ##STR89##                                      ##STR90##                                                                                                    ##STR91##                                      ##STR92##                                                                                                    ##STR93##                                      ##STR94##                                                                                                    ##STR95##                                      ##STR96##                                                                                                    ##STR97##                                      ##STR98##                                                                                                    ##STR99##                                      ##STR100##                                                                                                   ##STR101##                                     ##STR102##                                                                                                   ##STR103##                                     ##STR104##                                                                                                   ##STR105##                                     ##STR106##                                                                                                   ##STR107##                                     ##STR108##                                                                                                   ##STR109##                                     ##STR110##                                                                                                   ##STR111##                                     ##STR112##                    (1) H.sub.2 NNHCOC(CH.sub.3)CH.sub.2 (2)                                      Dehydration                                    CF.sub.2 CO.sub.2 CH.sub.2 C(CH.sub.3).sub.2 CH.sub.2 OH                                                     HOCH.sub.2 C(CH.sub.3).sub.2 CH.sub.2 OH       CF.sub.2 CO.sub.2 CH.sub.2 CHCH.sub.2                                                                        CH.sub.2CHCH.sub.2 OH                          CF.sub.2 CN                    (1) NH.sub.3                                                                  (2) Dehydration                                 ##STR113##                                                                                                   ##STR114##                                    __________________________________________________________________________

The functional group-terminated polyfluoropolyether compositions of thisinvention can be polymerized by well-known procedures to form a widerange of useful products. Generally, where the perfluoroolefin used toproduce the polyfluoropolyether composition of this invention istetrafluoroethylene, CF₂ ═CF₂, the polyfluoropolyether composition(Formula VI) is comprised of predominately, e.g., at least 80 weightpercent, difunctional product and, when polymerized, becomes an integralpart of the polymer chain. Generally, where the perfluoroolefin used toproduce the polyfluoropolyether composition of this invention ishexafluoropropylene, CF₃ CF═CF₂, the polyfluoropolyether composition(Formula VII) is comprised of predominately, e.g., at least 50 weightpercent, monofunctional product and, when polymerized, forms a pendantgroup on the polymer chain.

These functional group-terminated polyfluoropolyethers can bepolymerized to form polymers useful for the preparation of low surfaceenergy liners for aggressive adhesives (using, e.g., the proceduresdescribed in U.S. Pat. Nos. 4,472,480 and 4,567,073) molded articlessuch as chemically resistant and low temperature flexible hoses andgaskets and solid rocket propellant binder (using, e.g., the proceduresdescribed in U.S. Pat. No. 3,972,856), abrasion resistant oil and waterrepellent surface coatings for cookware (using, e.g., the proceduresdescribed in U.S. Pat. No. 3,950,588), ophthalmic devices such ascontact lenses, intraocular lenses, corneal lenses and implants and thelike, and in hydrated blends such as, for example, use as waterbarriers, sealants, water sorbents, electrophoresis gels, coatings forprosthetic devices, membrane films, vascular prosthetic devices,cartilage replacements, and coextruded hydrophilic composites (e.g.,catheters) (using, e.g., the procedures described in European PatentApplication No. 84305837.1). In addition to their utility as prepolymersfor the preparation of polymers, these functional group-terminatedpolyfluoropolyether compositions are also useful as lubricants,viscosity index additives for perhalogenated lubricants, hydraulicfluids (using, e.g., the procedures described in U.S. Pat. No.3,845,051), water and oil repellents, surface active agents andanti-corrosion agents, antistick or release agents for molds, flotationagents, and plasticizers for fluorinated plastics. In the procedures ofU.S. Pat. Nos. 4,472,480, 4,567,073, 3,972,856, 3,950,588, and 3,845,051and European Patent Application No. 84305837.1, the polyethers describedtherein are substituted by the appropriate functional or non-functionalpolyfluoropolyether of the present invention.

Polymerization of the functional polyfluoropolyether compositions of theinvention can be carried out using procedures well-known to thoseskilled in the art. For example, when the functional end group isacrylate or methacrylate, the polymerization of the polyfluoropolyethermay be carried out by employing initiators which generate free-radicalson application of an activating energy as is conventionally used in thepolymerization of ethylenically unsaturated monomers. Included amongfree-radical initiators are the conventional thermally activatedinitiators such as organic peroxides and organic hydroperoxides.

Photoinitiators may also be employed to initiate polymerization. Suchinitiators are well known and have been described, for example, inpolymerization art, e.g., Chapter II of "Photochemistry" by Calvert andPitts, John Wiley & Sons (1966). The preferred initiators arephotoinitiators which facilitate polymerization when the composition isirradiated, for example, by exposure to ultraviolet or electron beamirradiation.

Polymerization may also be carried out in bulk in a conventional manner.When the activating energy is ultraviolet light, the irradiation istypically carried out at a temperature of about 0° to 50° C. for 0.5minute to 5 hours or more. Following ultraviolet irradiation, thecomposition may be heated at 50° to 100° C. to complete thepolymerization.

When the activating energy is only heat, polymerization is usuallycarried out at a temperature from about 40° to 140° C. for about 5 to 50hours. The polymerization can also be carried out in stages. Thus, in afirst stage, the composition may be heated at 40° to 60° C. for about 5to 25 hours, and in a second stage it may be heated at 50° to 100° C.for 5 to 25 hours. It is to be understood, of course, that thepolymerization conditions are not limited to such temperature and timeconditions nor to the use of ultraviolet or heat as the initiatingenergy.

When shaped or molded articles such as gaskets or ophthalmic devices areprepared using the functional polyfluoropolyether compositions of theinvention, a mold of the desired configuration is charged with amaterial comprising the functional polyfluoropolyether composition andany other desired comonomer and the charge is polymerized by, forexample, one of the techniques previously described. Articles having thedesired final configuration may be obtained in this manner. Theresultant article may be machined and/or polished if desired usingtechniques known to the art.

Alternatively, the devices of the invention may be provided bypolymerizing the polyfluoropolyether into a rod, block, or sheetfollowed by cutting the article therefrom.

When a functional polyfluoropolyether composition is used as a releasecoating, for example, for pressure-sensitive adhesive tape, a solutionof the polyfluoropolyether composition, preferably a composition havingacrylate or methacrylate functionality, is coated on the substrate, forexample, a flexible film. The coating is then dried and thepolyfluoropolyether composition is polymerized to form a cohesivenetwork adhered to the substrate. An adhesive layer such as apoly(dimethylsiloxane) can then be releasably adhered to the polymerizedpolyfluoropolyether composition.

When the functional polyfluoropolyether composition has epoxyfunctionality, materials comprised thereof can be cured by a variety ofcuring agents as are described, together with the method for calculatingthe amount to be used, in the book by Lee and Neville, "Epoxy Resins,"pages 36 to 140, McGraw-Hill Book Company, New York, 1957. Useful curingagents include initiators such as amines and organic acids. Theepoxy-functional polyfluoropolyether compositions can also be cured bycatalytic agents that are either thermally-activated or photoactivated,e.g., Lewis acids, hindered Lewis acids, and onium salts.

The inert liquid compositions comprising polyfluoropolyethersrepresented by Formula V can be formed by subjecting either thecomposition comprising the peroxide poly(perfluorooxyalkylenes)represented by Formula III or the composition comprising thedeperoxidized polyfluoropolyether represented by Formula VIII to athermal treatment in the presence of an alkali metal hydroxide to yielda hydride-terminated polyfluoropolyether fluid. The hydride-terminatedmaterial can then be chlorinated to produce a chlorine-terminatedproduct. Alternatively, compositions comprising thepoly(perfluorooxyalkylenes) represented by Formula III or compositionscomprising the polyfluoropolyethers represented by Formula VIII may befluorinated to produce a perfluorinated inert liquid.

By thermal treatment in the presence of an alkali metal hydroxide,preferably sodium, potassium, or lithium hydroxide, or by treatment withfluorine, the carbonyl and carboxylic acid groups that are formed byhydrolysis of the carbonyl fluoride groups (hydrolysis can take placeeven in humid air) can be eliminated from the non-peroxidic compositionscomprising the polyfluoropolyethers represented by Formula VIII and boththe peroxide groups and the carbonyl fluoride and carboxylic acid groupscan be eliminated from the peroxidic compositions comprisingpoly(perfluorooxyalkylenes) represented by Formula III. When thecarbonyl groups are eliminated by thermal treatment in the presence ofan alkali metal hydroxide, there is used, for example, about 10 to 20%by weight of alkali metal hydroxide based on the weight of the productscomprising the poly(perfluorooxyalkylenes) represented by Formula III orthe polyfluoropolyethers represented by Formula VIII. Reaction time isgenerally from about three to ten hours at temperatures which aregradually raised, for example, from about 50° C. to about 200° C. to350° C., preferably about 250° C. There are obtained compositionscomprising inert polyfluoropolyethers represented by Formula V in whichX is hydrogen, the terminal groups --CF₂ H and --CHFCF₃ having beenformed. The hydrogens can be replaced by halogens including fluorine andchlorine, by processes well-known to those skilled in the art.

When the compositions comprising poly(perfluorooxyalkylenes) representedby Formula III or compositions comprising polyfluoropolyethersrepresented by Formula VIII are thermally treated in the presence offluorine, the terminal carbonyl and carboxylic acid groups areeliminated and terminal --C_(j) F_(2j+1) groups, such as --CF₃, --CF₂CF₃, and --C₄ F₉, are formed. This reaction is performed by heating thecompositions comprising the poly(perfluorooxyalkylenes) represented byFormula III or the polyfluoropolyethers represented by Formula VIII to atemperature, for example, between about 50° C. and 300° C. andsimultaneously introducing fluorine either neat or diluted with up to,for example, about ten parts by weight of an inert gas, e.g., nitrogenor argon. By-products of the reaction are carbon dioxide, carbonylfluoride, trifluoroacetyl fluoride, and other low-molecular weightvolatile compounds. Hydrogen fluoride is also obtained as a by-productwhen the treated material contains carboxylic acid groups.

The compositions comprising inert polyfluoropolyether liquidsrepresented by Formula V can be separated by distillation into fractionshaving boiling ranges from, for example, about 50° C. to more than 350°C. at 0.1 torr and viscosities ranging from less than one centistoke toseveral thousand centistokes at room temperature. The inert liquids ofthe present invention have various applications. The lower boilingfractions can be used as solvents, dielectric media, hydraulic fluids,and heat transfer fluids and the higher boiling fractions and stillresidues can be used as lubricants, especially in applications requiringboth low viscosity and inertness to harsh conditions such as those foundin semiconductor processing equipment.

The polyfluoropolyether liquids of this invention have severaladvantages over the prior art. For instance, in addition to having newunits in the backbone, viz., the perfluoromethyleneoxy andperfluoroethyleneoxy units with pendant perfluoroalkoxy groups, thefluids prepared from photooxidation ofhexafluoropropylene/perfluoro(alkyl vinyl) ether mixtures show largerb/c ratios (Formula III) than those prepared under identical conditionsfrom photooxidation of hexafluoropropylene alone. As shown in Example 2below, these changes in backbone structure can lead to improved fluidproperties. Also, as shown in Examples 33 and 34 below, cured coatingsof polymerized functional group-terminated compositions of thisinvention perform as release coatings, e.g., for siliconepressure-sensitive adhesives, more effectively than materials preparedfrom hexafluoropropylene alone. Further, the polymerized functionalpolyfluoropolyether compositions have low glass transition temperatures(Tg) which provide excellent low temperature flexibility to shapedarticles formed therefrom. Functional polyfluoropolyether compositionscomprising compounds of Formula VI generally have a Tg less than about-100° C. with some species having a Tg of less than -120° C. Functionalpolyfluoropolyether compositions comprising compounds of Formula VIIgenerally have a Tg less than about -78° C.

Although the b/c ratios in compositions prepared from photooxidation ofhexafluoropropylene alone can be increased by raising the reactiontemperature, this approach has some disadvantages. Temperatures above-30° C., the boiling point of hexafluoropropylene, require that thephotooxidation reaction be run at pressures above 1 atmosphere (if nosolvent is used), which involves construction of special equipment.Also, as the reaction temperature is raised, the molecular weight of thepolymeric photoproduct decreases, while the fraction of startingmaterial converted to non-recyclable oxidation products, such ashexafluoropropylene oxide, increases. Thus, addition of perfluoro(alkylvinyl) ether to hexafluoropropylene photooxidation provides a means ofvarying the relative content of --CF₂ O-- backbone groups in the polymerwithout substantially altering other reaction conditions.

Objects and advantages of this invention are further illustrated by thefollowing examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this invention.

In these examples, the structures of the poly(perfluoroalkylenes) andthe polyfluoropolyethers are determined by ¹⁹ F and proton NMR analysis.The backbone unit ratios are calculated from ratios of the integratedpeak intensities of the ¹⁹ F NMR spectrum. The number average molecularweights are determined by end group analysis.

EXAMPLE 1

A mixture of perfluoro(methyl vinyl) ether (35 g) andhexafluoropropylene (190 g) was condensed in a jacketed 250 mlAce/Hanovia tubular glass photoreactor equipped with quartz immersionwell, gas sparge tube, thermocouple, and an outlet leading to a refluxcondenser maintained at -65° C. Cooled fluorocarbon Fluorinert®FC-72(product of 3M Company) was circulated as a heat exchange fluid throughthe reactor jacket and cooled nitrogen was blown through the quartz wellto provide additional cooling and temperature control. Oxygen wasbubbled into the solution at a rate of 13 l/hr. This mixture wasirradiated with a Hanovia 100 watt medium-pressure mercury lamp with thereaction temperature regulated at -45° C. The reflux condenser returnedentrained starting materials to the reactor. Gases exiting the condenserwere scrubbed with aqueous potassium hydroxide before venting. After 6hours, the lamp was switched off and the reactor allowed to warm to roomtemperature overnight under oxygen. Remaining in the reactor were 90 gcolorless liquid. This product had an acitve oxygen content of 0.5weight percent by iodimetry, and exhibited a ¹⁹ F NMR spectrumconsistent with a peroxidic poly(perfluorooxyalkylene) productcomprising material having the structure represented by formula IIIwhere Q was --COF, --CF₂ COF, and --CF₂ COOH, the relative proportionsbeing 91 mol %, 9 mol %, and a trace, respectively, W was --CF₃, R¹ was--CF₃, and R² was --CF₃. In the product, b/c was 0.15, (d+d')/(b+c) was0.14, e/(b+c+d+d') was 0.05, d/d' was 0.28, and the number averagemolecular weight was 2400. The presence of incorporated perfluoro(methylvinyl) ether-derived units in the chain comes from observation of ¹⁹ FNMR signals at 54.5 ppm and 56.5 ppm (upfield from CFCl₃) attributableto pendant --OCF₃ groups, and at 96-99 ppm attributable to the methinefluorine of the the ##STR115## unit. The ¹⁹ F NMR spectrum showed theabsence of backbone units containing more than two catenary carbon atomsin the chain.

A 5.0 g sample of the above product was heated in a glass flask at 175°C. for 16 hr. After cooling, there remained 4.3 g liquid. Infraredspectroscopic analysis of this material revealed the presence offluoroformate, acid fluoride, and carboxylic acid end groups. By ¹⁹ FNMR, peroxide linkages were found to be absent, and the non-peroxidicproduct exhibited a structure consistent with that of a compositioncomprising the polyfluoropolyether represented by Formula VIII where W'was --CF₃ and (CF₃)₂ CFCF₂ --, the relative proportions being 93 mol %and 7 mol %, respectively, Q' was --COF, --CF₂ COF, --CF(CF₃)COF, and--CO₂ H, the relative proportions being 53 mol %, 7 mol %, 13 mol %, and27 mol %, respectively, R¹ was --CF₃, and R² was --CF₃. In the product,t/u was 0.15, (v+v')/(t+u) was 0.10, v/v' was 0.30, and the numberaverage molecular weight was 3000.

EXAMPLE 2

A jacketed, 250 ml tubular, stainless steel reactor was equipped with aquartz immersion well, gas sparge tube, two inlets for separateintroduction of monomers, a reflux condenser maintained at -70° C.,thermocouple, and temperature control equipment. Cooled Freon™-11,CFCl₃, was circulated through the reactor jacket and condenser as a heatexchange fluid, and cooled N₂ was blown through the quartz immersionwell. Hexafluoropropylene (253 g) was condensed into the reactor, andoxygen was bubbled through the liquid at a flow rate of 13 l/hr. Using acalibrated flow meter and metering valve, perfluoro(methyl vinyl) etherwas added continuously to the reactor at a rate of 5.5 g/hr. Thismixture was irradiated with a 100-watt Hanovia medium-pressure mercurylamp for 6 hr., with the reaction temperature maintained at -45° C. Atthe end of this period, the lamp and gas flows were stopped and thereactor was drained. Evaporation of volatiles left 115 g liquid productwhich was found to contain 0.8 g active oxygen by iodimetric titration.¹⁹ F NMR spectroscopy showed the peroxidic product to comprise materialhaving a structure consistent with a composition comprisingpoly(perfluorooxyalkylenes) represented by Formula III where W was--CF₃, Q was --COF and --CF₂ COF, the relative proportions being 92 mole% and 8 mol %, respectively, R¹ was --CF₃, and R² was --CF₃. In theproduct, b/c was 0.16, (d+d')/(b+c) was 0.13 and e/(b+c+d+d') was 0.08,d/d' was 0.22, and the number average molecular weight was 2500.

The above peroxidic product (102 g) was placed in a three-necked 250 mlflask equipped with mechanical stirrer, heating mantle, thermometer, anddistilling head. While stirring, 13 g ground potassium hydroxide wereadded in portions. After addition was complete and foaming had subsided,the mixture was heated slowly to 140° C. and maintained at 140°-150° C.for 3 hours. The temperature was then taken to 250° C. and kept therefor 30 minutes until gas evolution had subsided. Distilling from thereaction flask during this heating were 13 g water and low molecularweight fluorocarbon. After cooling, the flask residue was extracted with100 ml Freon™113 and filtered. Evaporation of the solvent left 61 gclear, colorless liquid. The infrared spectrum of this liquid showedabsence of carbonyl group absorption. By ¹⁹ F and proton NMR, end groupsof the types --OCF₂ H and --OCFHCF₃ were detected. The product comprisedmaterial consistent with a composition comprising polyfluoropolyethersrepresented by Formula V where R¹ was --CF₃, R² was --CF₃, --C_(j)F_(2j) X was a mixture of --CF₃, --CF₂ CF(CF₃)₂, --CF₂ H, and --CFHCF₃,the relative proportions being 49 mol %, 5 mol %, 34 mol %, and 12 mol%, respectively. In the product, g/h was 0.19, (i+i')/(g+h) was 0.10 andi/i' was 0.27. The number average molecular weight was 3000. Thematerial was fractioned in a CVC Lab-3 molecular still, and thedistillation cut with a boiling range of 160°-250° C./0.01 torr wasisolated. Viscosity of this cut was found to be 226 centistokes (cSt) at20° C., compared to 270 cSt for an identical control cut prepared in asimilar manner except for the omission of perfluoro(methyl vinyl) etherfrom the photooxidation reaction. The two fractions were shown by gelpermeation chromatography to have virtually the same molecular weightand polydispersities, with the molecular weight of the control samplebeing slightly lower.

The above described fractionated hexafluoropropylene/perfluoro(methylvinyl) ether copolyether cut (12.2 g) was heated at 250° C. under astream of Cl₂ for 4 hours. The product (11.9 g) showed no absorption inthe proton NMR spectrum. ¹⁹ F NMR showed that the hydride-containing endgroups had been replaced by --OCF₂ Cl, --OCFClCF₃, and --OCF₂ CFClCF₃.Other structural features were substantially unchanged.

EXAMPLE 3

Into the apparatus described in Example 2 were charged 252 ghexafluoropropylene. Flows of oxygen (13 l/hr) and perfluoro(-n-butylvinyl) ether (6.5 g/hr., added via syringe pump) were started and themixture was irradiated with a 100 watt Hanovia medium-pressure mercurylamp for 6 hours. Reaction temperature was kept at -45° C. Removal ofvolatiles left 118 g liquid product. The presence of incorporatedperfluoro(butyl vinyl) ether-derived units is shown by observation ofsignals in the ¹⁹ F NMR spectrum at 81 ppm (--OCF₂ CF₂ CF₂ CF₃), 127 ppm(--OCF₂ CF₂ CF₂ CF₃), and 96 ppm ##STR116## upfield from CFCl₃. Noevidence of unreacted vinyl ether was found in the reaction mixture. Theaverage structure of the peroxidic material corresponded to acomposition comprising poly(perfluorooxyalkylenes) represented byFormula III where W was --CF₃, Q was --COF and --CF₂ COF, the relativeproportions being 91 mol % and 9 mol %, respectively, R¹ was --CF₃, andR² was --C₄ F₉. In the product, b/c was 0.09, (d+d')/(b+c) was 0.07,e/(b+c+d+d') was 0.08, d/d' was believed to be between about zero and0.5 and the number average molecular weight was 2900.

EXAMPLE 4

A jacketed 2-liter stainless steel reactor fitted with a quartzimmersion well, two fritted sparge tubes, a thermocouple, and a refluxcondenser was cooled by circulating cooled Freon™-11 fluid through thejacket and the condenser. The vessel was charged with 1700 ml ofdichlorodifluoromethane that was cooled in the reactor to -40° C., whichtemperature was maintained during the course of the reaction. There werethen introduced into the reactor through the sparge tubes 1.90 g/mintetrafluoroethylene that had been passed through a column of activatedcarbon to remove d-limonene inhibitor, 0.18 g/min perfluoro(propylvinyl) ether, and 1.42 g/min oxygen. A Hanovia 200 watt medium-pressuremercury lamp, inserted in the immersion well, was then turned on. Aftertwo hours, the lamp and fluid flows were stopped, the reaction mixtureremoved and the CF₂ Cl₂ allowed to evaporate. There remained 106 g ofcolorless liquid having by ¹⁹ F NMR a peroxide content of 2.39 percentby weight and an average structure corresponding to a compositioncomprising poly(perfluorooxyalkylenes) represented by Formula III whereQ was --CF₂ COOH, and W was substantially the same as Q with some --CF₂Cl and --CF₂ CF₂ Cl also present, R¹ was fluorine, and R² was --C₃ F₇.In the product, b/c was 0.74, (d+d')/(b+c) was 0.0106, e/(b+c+d+d') was0.149, and d/d' was 1.80 as indicated by signals upfield from CFCl₃ at81.5 ppm (--OCF₂ CF₂ CF₃), 129.8 ppm (--CF₂ CF₂ CF₃), and 96.9 ppm and98.4 ppm ##STR117## These latter peaks were obscured by peroxide peaksin the crude photooxidation product, but were detected in the materialupon thermal deperoxidation. The relative distribution of end groups Qand W was 38 mol % --CF₂ COOH, 34 mol % --CF₂ Cl, and 28 mol % --CF₂ CF₂Cl. The number average molecular weight was 40,000.

EXAMPLE 5

The procedure of Example 4 was repeated with the exception that 0.15g/min of perfluoro(ethyl vinyl) ether was used in place of 0.18 g/min ofperfluoro(propyl vinyl) ether. The reaction product had a number averagemolecular weight of 24,000. ¹⁹ F NMR spectrometric data indicated thatthe peroxidic reaction product was consistent with a compositioncomprising poly(perfluorooxyalkylenes) represented by Formula III whereR¹ was fluorine, R² was --C₂ F₅, Q was --CF₂ COOH, W was --CF₂ COOH,with minor amounts of --CF₂ Cl, --CF₂ CF₂ Cl, and --CF₃ also present. Inthe product, b/c was 0.74, (d+d')/(b+c) was 0.0195, e/(b+c+d+d') was0.176, and d/d' was 1.81. The relative distribution of end groups Q andW was 75 mol % --CF₂ COOH, 14 mol % --CF₂ Cl, 11 mol % --CF₂ CF₂ Cl, anda trace of --CF₃.

The above peroxidic reaction product was thermally treated to partiallyremove peroxide groups by heating to 155° C. over a period of 4 hoursand holding at 155° C. for 125 hours. The product obtained was acomposition comprising poly(perfluorooxyalkylenes) represented byFormula III where Q was --CF₂ COOH, W was --CF₂ COOH, --CF₂ CF₂ Cl,--CF₃, and --CF₂ Cl. In the product, b/c was 1.19, (d+d')/(b+c) was0.0113, e/(b+c+d+d') was 0.0117, d/d' was 1.17, and the number averagemolecular weight was 16,000. The relative distribution of end groups Qand W was 68 mol % --CF₂ COOH, 14 mol % --CF₂ Cl, 10 mol % --CF₂ CF₂ Cl,and 8 mol % --CF₃.

EXAMPLE 6

Into the apparatus described in Example 2 were condensed 266 ghexafluoropropylene. An oxygen flow of 7 l/hr was started through theliquid, and the mixture irradiated for 6 hours at a temperature of -45°C., with a 100-watt Hanovia medium-pressure mercury lamp. During thefirst 5 hours, 79 g perfluoro(2-butoxypropyl vinyl) ether, n--C₄ F₉OCF(CF₃)CF₂ OCF═CF₂, bp 117°-125° C. (90% purity by gas chromatographicanalysis), were added continuously via syringe pump at the rate of 15.8g/hr. At the end of 6 hours, the lamp was shut off and the reactor wasdrained. Removal of 25° C. volatiles left 164 g liquid. Analysis of thisproduct by ¹⁹ F NMR showed no unreacted vinyl ether. A portion of theproduct (153 g) was heated in a glass 250 ml round-bottom flask to 250°C. over a period of 2 hr and then held at 250° C. for an additional 12hr. Volatile material which distilled out during pyrolysis was collectedin an amount of 43.7 g. This material was shown by ¹⁹ F NMR spectrometryto be primarily a mixture of ##STR118## the latter present as animpurity in the starting material. No unreacted vinyl ether wasrecovered.

The pyrolysis residue amounted to 90 g. To this was added 9.0 g powderedpotassium hydroxide. The flask was fitted with a mechanical stirrer anda heating mantle, and heating and stirring were begun. The mixture washeld at 150° C. for 2 hours then raised to 250° C. for 1 hour, afterwhich time gas evolution had stopped and heat was shut off. A total of5.5 g water and low-molecular weight fluorocarbon distilled off duringthe heating to 250° C.

The distilled reaction product was extracted with Freon™113 and filteredthrough a cake of silica gel and activated carbon. The filter cake waswashed several times with Freon™113, and the washings and filteredsolution combined and evaporated to constant weight on a rotaryevaporator. This left 72.9 g clear, colorless liquid which by infraredanalysis showed no carbonyl absorption. ¹⁹ F NMR spectrometric analysisshowed the product to be a composition comprising polyfluoropolyethersrepresented by Formula V, where R¹ was --CF₃, R² was ##STR119## theterminal groups, --C_(j) F_(2j) X, were a mixture of --CF₃, --CF₂CF(CF₃)₂, --CF₂ H, and --CFHCF₃, the relative distribution being 43 mol%, 8 mol %, 34 mol % and 15 mol %, respectively. In the product g/h was0.13, i/i' was believed to be between about zero and 0.5, (i+i')/(g+h)was 0.09, and g+h+i+i' was about 15. The presence of incorporated vinylether in the polyfluoropolyether chain was provided by observation of ¹⁹F NMR signals at 97 ppm, 81 ppm and 126 ppm upfield from CFCl₃. Thenumber average molecular weight was 2700.

The liquid product from the above reaction was heated at 250° C. under aslow stream of Cl₂ for 6 hours. After cooling and purging with N₂, thereremained 70.4 g clear, colorless liquid. ¹⁹ F NMR spectroscopy of thisproduct showed a structure mostly unchanged from that of thehydride-terminated starting material, except that the --CF₂ H and--CFHCF₃ end groups had been replaced by --CF₂ Cl, --CFClCF₃ and --CF₂CFClCF₃ end groups. This product (30.1 g) was vacuum distilled into thefollowing cuts.

    ______________________________________                                        CUT        BOILING RANGE MASS     WT. %                                       ______________________________________                                        I          67-100° C./0.1 torr                                                                  0.97 g    3.3                                        II        100-150° C./0.1 torr                                                                  2.59 g    8.7                                        III       150-250° C./0.2 torr                                                                  9.59 g   32.4                                        IV        250-270° C./0.4 torr                                                                  3.84 g   13.0                                        Residue   >270° C./0.4 torr                                                                     12.63 g  42.6                                        ______________________________________                                    

¹⁹ F NMR spectrometric analysis of the distillation cuts revealed thatthe (i+i')/h ratio, indicative of vinyl ether incorporation, wasessentially the same in each cut and largely unchanged from that in theunfractionated material.

EXAMPLE 7

To the 2-liter jacketed stainless steel reactor described in Example 4were added 2720 g hexafluoropropylene and 28 g perfluoro(methyl vinyl)ether. The temperature of the mixture was regulated at -40° C., and a200-watt Hanovia medium-pressure mercury arc was ignited in the quartzwell. A flow of approximately 0.9 g/min. tetrafluoroethylene was begunthrough a column of activated carbon to remove d-limonene inhibitor, andthen mixed with a flow of approximately 2.42 g/min. oxygen. This gasmixture was bubbled through the liquifiedhexafluoropropylene/perfluoro(methyl vinyl) ether mixture in thereactor. A reflux condenser operating at -80° C. was used to returnunreacted entrained monomers to the reactor while allowing carbonylfluoride and oxygen to escape. The off-gas stream was scrubbed withaqueous potassium hydroxide solution before venting.

After one hour of photolysis, the gas flows and lamp were turned off,and the reactor contents were collected. Unreacted hexafluoropropyleneand other volatile materials were allowed to distill off, leaving behind347 g clear, colorless fluid.

This liquid product exhibited a ¹⁹ F NMR spectrum consistent with aproduct comprising poly(perfluorooxyalkylenes) represented by FormulaIII where W was --CF₃, Q was --COF, R¹ was --F and --CF₃, the ratioF/CF₃ was 0.89, and R² was --CF₃. In the product, b/c was 0.02,(d+d')/(b+c) was 0.01, e/(b+c+d+d') was 0.35, d/d' was believed to bebetween about zero and 0.5, and the number average molecular weight was4450.

EXAMPLE 8

Into the apparatus described in Example 1 were condensed 200 ghexafluoropropylene and 60 g perfluoro(propyl vinyl) ether (C₃ F₇OCF═CF₂). Oxgyen flow of 13 l/hr through the liquid was started, and themixture was irradiated for 6 hr. at a temperature of -45° C. with a100-watt Hanovia medium-pressure mercury lamp. After this period thelamp was shut off, and the reactor contents were allowed to warm to roomtemperature. Remaining were 48 g colorless liquid. Further removal ofvolatiles under vacuum left 42 g product. This material exhibited a ¹⁹ FNMR spectrum consistent with a product comprisingpoly(perfluorooxyalkylenes) represented by Formula III in which Q was--COF, R¹ was --CF₃, R² was --C₃ F₇, and W was --CF₃. In the product,b/c was 0.50, (d+d')/(b+c) was 0.60, e/(b+c+d+d') was 0.14, d/d' wasbelieved to be between about zero and 0.5, and the number averagemolecular weight was 3800. Active oxygen content was 1.2 weight percentby iodimetry. No unreacted starting materials were observed in thephotoproduct.

Twenty grams of the peroxidic photooxidation product were heated in asand bath at 250° C. for 12 hr. A total of 2.1 g volatile low-molecularweight species distilled out during the pyrolysis. Remaining in theflask following heat treatment were 11.7 g liquid. Iodimetric and ¹⁹ FNMR analysis showed the absence of peroxidic linkages, and infraredanalysis showed acid fluoride (--COF) and trifluoromethyl ketone (--CF₂COCF₃) end groups to be present. The ¹⁹ F NMR data was consistent with aproduct comprising polyfluoropolyethers represented by Formula VIII inwhich Q' was --CF₂ COF, --CF(CF₃)COF, and --COCF₃, the relativedistribution being 58 mol %, 27 mol % and 15 mol %, respectively, R¹ was--CF₃, R² was --C₃ F₇, and W was --CF₃, --C₃ F₇, and --CF₂ CF(CF₃)₂, therelative distribution being 50 mol %, 38 mol %, and 12 mol %,respectively. In the product, t/u was 0.60, (v+v')/(t+u) was 0.46, v/v'was believed to be between about zero and 0.5, and the number averagemolecular weight was 1900.

EXAMPLE 9

A peroxidic poly(perfluorooxyalkylene) fluid comprisingpoly(perfluorooxyalkylenes) represented by Formula III, where Q was--CF₂ COOH and --COF, W was --C₂ F₄ Cl, --CF₂ Cl, and --CF₃, therelative proportions of the Q and W being 46 mol % --CF₂ COOH, 30 mol %--C₂ F₄ Cl, 24 mol % --CF₂ Cl, and trace amounts of --COF and --CF₃, R¹was fluorine, R² was --CF₃, b/c was 0.80, (d+d')/(b+c) was 0.0403,e/(b+c+d+d') was 0.157, d/d' was 2.57, and having a number averagemolecular weight of 73,000, was prepared by photooxidation oftetrafluoroethylene and perfluoro(methyl vinyl) ether as in Example 4.The peroxidic poly(perfluoroxyalkylene) (222 g) was added by remotecontrol to a reaction vessel equipped with a mechanical stirrer and anitrogen purge. Inside an explosion-proof barricade, while stirring, thereactor and its contents were heated by remote control at a rate of 0.6°C. per minute to a temperature of 175° C. and held at this temperaturefor 73/4 hours at which time the temperature was reduced to 25° C. Therewas obtained a 69% yield of reaction product that had a number averagemolecular weight of 19,000, and comprised poly(perfluorooxyalkylenes)represented by Formula III where Q was --CF₂ COOH and --COF, W was --C₂F₄ Cl, --CF₂ Cl, and --CF₃, R¹ was fluorine, R² was --CF₃, b/c was 1.27,(d+d')/(b+c) was 0.0469, and e/(b+c+d+d') was 0.0403, and d/d' was 2.60as determined by ¹⁹ F NMR analysis. The relative distribution of the Qand W end groups was 47 mol % --CF₂ COOH, 14 mol % --C₂ F₄ Cl, 13 mol %--CF₂ Cl, and 26 mol % --CF₃.

Into a 3-neck round bottom flask equipped with a stirrer, condensercooled at 0° C., and an addition funnel were placed 40.1 g of the abovereduced peroxidic product, 39.3 g Freon™113(1,1,2-trifluoro-2,2,1-trichloroethane), and 6.1 g methanol. Thecontents of the flask were blanketed by a stream of nitrogen and themixture heated by a fluid bath to 55° C. When reflux of the contentsbegan, there was added over a 30 minute period a mixture of 12.2 gmethanol and 18.7 g of 57% unstabilized hydriodic acid. The mixture wasthen allowed to reflux for 10 hours, after which it was cooled, thefluorocarbon layer separated and washed three times with an equal volumeof sulfur dioxide saturated water and then two times with deionizedwater. After removal of volatiles by distillation, 32.1 g of diesterwere obtained that by ¹⁹ F NMR spectral analysis had a number averagemolecular weight of 2180 and comprised polyfluoropolyethers representedby Formula VI where R⁶ was --CF₂ COOCH₃ and --CF₂ COOH, Y was --CF₂COOCH₃, --CF₂ COOH, --C₂ F₄ Cl, --CF₂ Cl, and --CF₃, R' was fluorine, R²was --CF₃, k/l was 1.40, and (p+p')/(k+l) was 0.0465, and p/p' was 2.48.The relative proportions of the R⁶ and Y end groups was 87 mol % --CF₂COOCH₃, 7 mol % --CF₂ COOH, 3 mol % --CF₃, 1 mol % --C₂ F₄ Cl and 2 mol% --CF₂ Cl.

EXAMPLE 10

The procedure of Example 9 was repeated using a hold time of 7.5 hoursand a peroxidic poly(perfluorooxyalkylene) fluid comprisingpoly(perfluorooxyalkylenes) represented by Formula III where Q was --CF₂COOH and --COF, W was --C₂ F₄ Cl, --CF₂ Cl, and --CF₃ with the relativeproportions of end groups being 25 mol % --CF₂ COOH, 10 mol % --COF, 35mol % --C₂ F₄ Cl, 30 mole % --CF₂ Cl, and trace amounts of --CF₃, R¹ wasfluorine, R² was --CF₃, b/c was 0.78, (d+d')/(b+c) was 0.0700,e/(b+c+d+d') was 0.151, d/d' was 3.77, and had a number averagemolecular weight of 55,000. There was obtained a 65% yield of reducedperoxidic product comprising poly(perfluorooxyalkylenes) represented byFormula III where Q was --CF₂ COOH and --COF, W was --C₂ F₄ Cl,--CF.sub. 2 Cl, and --CF₃, with relative proportions of the end groups Qand W being 29 mol % --CF₂ COOH, 23 mol % --COF, 20 mol % --C₂ F₄ Cl, 28mol % --CF₂ Cl, and trace amounts of --CF₃, R¹ was fluorine, R² was--CF₃, b/c was 1.24, (d+d')/(b+c) was 0.0769, e/(b+c+d+d') was 0.0433,d/d' was 2.02, and a number average molecular weight of 24,000.

Thirty grams of the above reduced peroxidic product were treated withhydriodic acid according to the procedure described in Example 9. Therewere obtained 27.6 grams of polyfluoropolyether dimethyl esters having anumber average molecular weight of 2070 and comprisingpolyfluoropolyesters represented by Formula VI where R⁶ was --CF₂COOCH₃, --CF₂ COOH, --C₂ F₄ Cl, --CF₂ Cl, and --CF₃, Y was --CF₂ COOCH₃and --CF₂ COOH, R¹ was fluorine, R² was --CF₃, k/l was 1.48,(p+p')/(k+l) was 0.0872, and p/p' was 1.87. The relative proportions ofthe end groups R⁶ and Y were about 81 mol % --CF₂ COOCH₃, 8 mol % --CF₂COOH, 2 mol % --CF₂ Cl, 2 mol % --C₂ F₄ Cl, and 7 mol % --CF₃.

EXAMPLE 11

The peroxidic reduction procedure of Example 9 was repeated using an 8hour hold time and a peroxidic poly(perfluorooxyalkylene) liquidcomprising poly(perfluorooxyalkylenes) represented by Formula III whereR¹ was fluorine, R² was --C₃ F₇, Q was --CF₂ COOH and --COF, W was --CF₂Cl and --C₂ F₄ Cl, b/c was 0.51, (d+d')/(b+c) was 0.0941, e/(b+c+d+d')was 0.206, d/d' was 1.96, and a number average molecular weight of131,000 that had been prepared as described in Example 4. There wasobtained a 31% yield of reduced peroxidic product comprisingpoly(perfluorooxyalkylenes) represented by Formula III where R¹ wasfluorine, R² was --C₃ F₇, Q was --CF₂ COOH and --COF, W was --C₂ F₄ Cl,--CF₂ Cl, and --CF₃, b/c was 1.17, (d+d')/(b+c) was 0.0760, e/(b+c+d+d')was 0.0380, d/d' was 2.03 and a number average molecular weight of16,000. The relative proportions of the end groups Q and W were 34 mol %--COF, 31 mol % --CF₂ COOH, 13 mol % --C₂ F₄ Cl, 15 mol % --CF₂ Cl and 7mol % --CF₃.

Twenty-one grams of the reduced peroxidic product were treated withhydriodic acid according to the procedure described in Example 9. Therewere obtained 18.3 g of polyfluoropolyethers comprisingpolyfluoropolyether dimethyl esters represented by Formula VI where R¹was fluorine, R² was --C₃ F₇, R⁶ was --CF₂ COOCH₃, --CF₂ COOH, --C₂ F₄Cl, --CF₂ Cl, and --CF₃, Y was --CF₂ COOCH₃ and --CF₂ COOH, k/l was 1.39(p+p')/(k+l) was 0.0768, p/p' was 1.90, and a number average molecularweight of 2420. The relative proportions of the end groups R⁶ and Y wasabout 90 mol % --CF₂ COOCH₃, 6 mol % --CF₂ COOH, 1 mol % --C₂ F₄ Cl, 2mol % --CF₂ Cl, and 1 mol % --CF₃.

EXAMPLE 12

The peroxidic reduction procedure of Example 9 was repeated using an8.25 hour hold time and a peroxidic poly(perfluorooxy-alkylene) liquidcomprising poly(perfluorooxyalkylenes) represented by Formula III whereQ was --CF₂ COOH and --COF, W was --CF₂ Cl and --C₂ F₄ Cl, with relativeproportions of the end groups being 44 mol % --CF₂ COOH, 29 mol % --CF₂Cl, and 27 mol % --C₂ F₄ Cl, R¹ was fluorine, R² was n--C₄ F₉, b/c was0.64, (d+d')/(b+c) was 0.0153, e/(b+c+d+d') was 0.158, d/d' was 3.29,and a number average molecular weight of 91,000, that had been preparedby the photooxidation of a mixture of tetrafluoroethylene andperfluoro(butyl vinyl) ether. There was obtained a 49% yield of reducedperoxidic product comprising poly(perfluorooxyalkylenes) represented byFormula III where Q was --CF₂ COOH and --COF, W was CF₂ Cl and C₂ F₄ Cl,with relative proportions of the end groups Q and W being 38 mol %--COF, 11 mol % --CF₂ COOH, 28 mol % --CF₂ Cl and 23 mol % --C₂ F₄ Cl,R¹ was fluorine, R² was n--C₄ F₉, b/c was 1.12, (d+d')/(b+c) was 0.0134,e/(b+c+d+d') was 0.0431, d/d' was 3.23, and a number average molecularweight of 40,000.

Thirty-three grams of the reduced peroxidic product were treated withhydriodic acid according to the procedure described in Example 9. Therewere obtained 29 grams of polyfluoropolyether dimethyl esters having anumber average molecular weight of 2030, and comprisingpolyfluoropolyether dimethyl esters represented by Formula VI where R⁶was --CF₂ COOCH₃, --CF₂ COOH, --C₂ F₄ Cl, and --CF₂ Cl, Y was --CF₂COOCH₃ and --CF₂ COOH, k/l was 1.28, (p+p')/(k+l) was 0.0148, and p/p'was 3.00. The relative proportions of the end groups R⁶ and Y were 93mol % --CF₂ COOCH₃, 4 mol % --CF₂ COOH, 2 mol % --CF₂ Cl, and 1 mol %--C₂ F₄ Cl.

EXAMPLE 13

The peroxidic reduction procedure of Example 9 was repeated using a 7.5hour hold time and a peroxidic poly(perfluorooxyalkylene) fluid having anumber average molecular weight of 43,000 and comprisingpoly(perfluorooxyalkylenes) represented by Formula III where Q waspredominately --COF with a trace amount of --CF₂ COOH, W was --CF₂ Cland --C₂ F₄ Cl, 33 mol % and 67 mol %, respectively, R¹ was fluorine, R²was ##STR120## b/c was 0.75, (d+d')/(b+c) was 0.0158, e/(b+c+d+d') was0.154, and d/d' was 3.0, which had been prepared by photooxidation of amixture of tetrafluoroethylene and perfluoro(butyloxypropyl vinyl)ether. There was obtained a 65% yield of reduced peroxidic productcomprising poly(perfluorooxyalkylenes) represented by Formula III whereQ was --COF and --CF₂ COOH, W was --C₂ F₄ Cl, --CF₂ Cl, and --CF₃, withrelative proportions of the end groups Q and W being 9 mol % --COF, 33mol % --CF₂ COOH, 15 mol % --CF₃, 26 mol % --CF₂ Cl, and 18 mol % --C₂F₄ Cl, R¹ was fluorine, R² was ##STR121## b/c was 1.24, (d+d')/(b+c) was0.011, e/(b+c+d+d') was 0.0472, d/d' was 2.60, and a number averagemolecular weight of 16,000.

Thirty-six grams of the reduced peroxidic product were treated withhydroiodic acid according to the procedure described in Example 9. Therewere obtained 31.6 g of polyfluoropolyether dimethyl esters having anumber average molecular weight of 2180 and comprisingpolyfluoropolyethers represented by Formula VI where R¹ was fluorine, R²was ##STR122## R⁶ was --CF₂ COOCH₃, --CF₂ COOH, --CF₃, --CF₂ Cl, and--C₂ F₄ Cl, Y was --CF₂ COOCH₃, and --CF₂ COOH, the relative proportionsof the end groups R⁶ and Y being 89 mol % --CF₂ COOCH₃, 4 mol % --CF₂COOH, 1 mol % --CF₃, 3 mol % --CF₂ Cl, and 3 mol % --C₂ F₄ Cl, k/l was1.43, (p+p')/(k+l) was 0.0112 and p/p' was 2.83.

EXAMPLE 14

Into a 3-neck round bottom flask equipped with a mechanical agitator, acondenser having circulating fluid at 0° C., and an addition funnel wereplaced 85 ml tetrahydrofuran, 1.64 g zinc chloride, and 0.88 g sodiumborohydride. The flask was purged for several minutes with nitrogen andthe flask heated by an fluid bath at 65° C. When reflux began, there wasadded a solution of 15.0 g of the polyfluoropolyether dimethyl esters ofExample 10 in 32 ml of Fluorinert®FC-75 (a fluorocarbon solventavailable from 3M). The mixture was left at reflux for 16 hours. Themixture was allowed to cool to 25° C. and then 12.7 g of 37% aqueoushydrochloric acid were added over a period of 30 minutes. The mixturewas stirred for another 30 minutes, the fluorocarbon layer separated andwashed two times with an equal volume of deionized water. Afterstripping off the volatiles at 55° C. under 20 torr, there were obtained13.3 g of a product comprising polyfluoropolyether diols represented byFormula VI where R¹ was fluorine, R² was --CF₃, R⁶ was --CF₂ CH₂ OH,--CF₃, --CF₂ Cl, and --C₂ F₄ Cl, Y was --CF₂ CH₂ OH, with relativeproportions of end groups R⁶ and Y being 90 mol % --CF₂ CH₂ OH, 6 mol %--CF₃, 2 mol % --CF₂ Cl, and 2 mol % --C₂ F₄ Cl. In the product, k/l was1.45, (p+p')/(k+l) was 0.0845, p/p' was 1.83, and the number averagemolecular weight was 2180.

EXAMPLE 15

In a similar manner to that described in Example 14, the diesters ofExample 9 were reduced to a product comprising polyfluoropolyether diolsrepresented by Formula VI where R¹ was fluorine, R² was --CF₃, R⁶ was--CF₂ CH₂ OH, --CF₃, --CF₂ Cl, and --C₂ F₄ Cl, Y was --CF₂ CH₂ OH, withrelative proportions of end groups R⁶ and Y being 94 mol % --CF₂ CH₂ OH,2 mol % --CF₃, 2 mol % --CF₂ Cl, and 2 mol % --C₂ F₄ Cl. In the product,k/l was 1.34, (p+p')/(k+l) was 0.0472, and p/p' was 2.63, and the nunberaverage molecular weight was 2560.

The polyfluoropolyether diols (13.15 g) were reacted withisocyanatoethyl methacrylate (1.45 g) and a drop of dibutyltin dilaurateto form polyfluoropolyether urethane dimethacrylates. Thedimethacrylates were mixed with 0.5 weight percent Darocur™1173,available from EM Chemicals, EM Industries Co., then polymerized betweentwo sheets of polyester film by using a 275-watt sunlamp (available fromGeneral Electric Company) to form a clear, flexible material suitablefor use as contact lens material.

EXAMPLE 16

The procedure of Example 14 was repeated using the polyfluoropolyetherdimethyl esters of Example 13 in place of those of Example 10. Therewere obtained 12.7 g of a product comprising a polyfluoropolyether diolrepresented by Formula VI where R¹ was fluorine, R² was ##STR123## R⁶was --CF₂ CH₂ OH, --CF₃, --CF₂ Cl, and --C₂ F₄ Cl, Y was --CF₂ CH₂ OH,with the relative proportions of the end groups R⁶ and Y being 91 mol %--CF₂ CH₂ OH, 2 mol % --CF₃, 4 mol % --CF₂ Cl, and 3 mol % --C₂ F₄ Cl.In the product, k/l was 1.44, (p+p')/(k+l) was 0.015, p/p' was 2.50, andthe number average molecular weight was 2470.

EXAMPLE 17

Into a 50 ml flask equipped with stirrer, thermometer, reflux condenser,and means for maintaining the flask contents under inert gas were placed1.50 g of a diol product, prepared as described in Example 14, 5 ml ofFreon™113, 3 ml of glyme, and 0.01 g 18-crown-6 phase transfer catalyst(available form Aldrich Chemical Co.). A flow of argon was initiated andthere was added 0.14 g finely crushed potassium hydroxide and 0.50 gallyl benzene sulfonate. The mixture was heated to 45° C. and held atthis temperature for 20 hours, during which time a white precipitateformed and after which time, thin layer chromatography indicated thatthe hydroxyl groups had disappeared. About equal volumes of Freon™113and water were then added, the mixture shaken, the phases separated, theFreon™ phase removed and washed with 10% aqueous sodium bicarbonate,washed with water, and placed over anhydrous magnesium sulfate for 24hours. The mixture was filtered and solvents were removed bydistillation yielding about 1.5 g of clear, colorless, low viscosityfluid. Proton NMR spectroscopy confirmed that the end groups --CF₂ CH₂OH had been converted to --CF₂ CH₂ OCH₂ CH═CH₂.

EXAMPLE 18

Into a 50 ml flask equipped with stirrer, thermometer, and means formaintaining the flask contents under inert gas were placed 1.2 g of adiol product that was prepared as described in Example 14, 106 mgisocyanatoethyl methacrylate and a small drop of dibutyltin dilaurate.The mixture was heated to 40° C. and held overnight at 30°-40° C. Theclear product was extracted with FC-75, treated with a mixture ofactivated carbon and anhydrous magnesium sulfate, filtered andconcentrated to give 1.13 g of a viscous fluid having infraredabsorption for NH of 3320 cm⁻¹, C--H of 2950 cm⁻¹, C═O of 1740 and 1710cm⁻¹, and C═C of 1630 cm⁻¹. Proton NMR spectroscopy confirmed that theend groups --CF₂ CH₂ OH had been converted to ##STR124##

EXAMPLE 19

The procedure of Example 18 was repeated using, in place ofisocyanatoethyl methacrylate, 0.37 ml of isocyanatopropyltriethoxysilane. A clear, colorless, low viscosity fluid was obtained.Proton NMR spectroscopy confirmed that the end groups --CF₂ CH₂ OH hadbeen converted to ##STR125##

EXAMPLE 20

Into a dry Schlenk tube under argon atmosphere were placed 1.50 g of adiol product, prepared as described in Example 14, and 10 ml Freon™113.To this solution was added by syringe 0.24 ml toluene-2,4-diisocyanateand 1 drop of dibutyltin dilaurate. After 3 hours, the mixture wasconcentrated under vacuum and taken up into 5 ml FC-75. This solutionwas shaken with anhydrous magnesium sulfate and activated carbon,filtered under argon, and concentrated to a clear colorless, lowviscosity fluid product whose viscosity rapidly increased on contactwith atmospheric moisture. Infrared spectroscopy indicated the presenceof a urethane linkage and isocyanate functionality. Proton NMRspectroscopy confirmed that the end groups --CF₂ CH₂ OH had beenconverted to ##STR126## (The isomers being those having the --CH₃ inpositions 2, 4, and 6.)

EXAMPLE 21

Into a 50 ml flask equipped with a stirrer and means for maintaining theflask contents under inert gas, were placed 1.50 g of apolyfluoropolyether diester product, prepared as described in Example12, and 124 microliters of allylamine and the mixture was stirred at 24°C. for 18 hours. At the end of this time, infrared spectra of thereaction mixure indicated the disappearance of the ester absorption andappearance of amide absorption at 1700 cm⁻¹. The product was dissolvedin Freon ™113, washed with 1% aqueous HCl, washed with water, and driedover anhydrous magnesium sulfate. On removal of solvent, a cloudy fluidwas obtained which was dissolved in Fluorinert^(R) FC-75, treated withactivated carbon and magnesium sulfate, filtered, and concentrated to aclear, colorless fluid. Proton NMR spectroscopy showed that the endgroups --CF₂ COOCH₃ had been converted to ##STR127##

EXAMPLE 22

In equipment as described in Example 21 were placed 1.50 g of apolyfluoropolyether diester product prepared as described in Example 9and 94.8 microliters of 2-aminoethanol and the mixture stirred at 24° C.overnight. The resulting fluid was dissolved in Fluorinert™FC-75,treated with activated carbon and anhydrous magnesium sulfate, filteredand concentrated to yield a clear colorless fluid. By infrared andproton NMR spectroscopy, the fluid was found to have absorption peakscharacteristic of amide NH, --OH, and --CH₂ -- groups indicating thatthe end groups --CF₂ COOCH₃ had been converted to ##STR128##

EXAMPLE 23

The process of Example 22 was repeated using 440 microliters of3-aminopropyltriethoxysilane in place of the 2-aminoethanol. By infraredspectroscopy, the fluid product was observed to have an amide absorptionat 1700 cm⁻¹ in place of the ester absorption at 1790 cm⁻¹. Proton NMRspectroscopy indicated that the end groups --CF₂ COOCH₃ had beenconverted to ##STR129##

EXAMPLE 24

Into a 3 neck round bottom flask, equipped with a stirrer, a condensercooled at 0° C., and an addition funnel, were placed 5.02 g of apolyfluoropolyether diol product prepared as in Example 15, and 6.17 mlof Freon™113 and 0.62 ml of triethylamine. The contents of the flaskwere blanketed by a stream of nitrogen and a solution of 0.60 ml ofacryloyl chloride in 3.05 ml of Freon™113 were added over a period of 30minutes to the contents of the flask. Stirring of the mixture wascontinued for 16 hours, after which, there was added a solution of 0.27g triethylamine in 0.22 g water. The mixture was stirred for anadditional 30 minutes, the fluorocarbon layer separated and washed twotimes with 37% hydrochloric acid and two times with deionized water.After removal of volatile materials, analysis of the residual fluidshowed the reaction product comprised polyfluoropolyether diacrylatesrepresented by Formula VI where R⁶ was ##STR130## --CF₃, --CF₂ Cl, and--C₂ F₄ Cl, Y was ##STR131## with relative proportions of the end groupsR⁶ and Y being 92 mol % ##STR132## 2 mol % --CF₃, 4 mol % --CF₂ Cl, and2 mol % --C₂ F₄ Cl, R¹ was fluorine, and R² was --CF₃. In the product,k/l was 1.37, (p+p')/(k+l) was 0.0475, p/p' was 2.50, and the numberaverage molecular weight was 3000.

EXAMPLE 25

Into a 100 ml flask equipped with stirrer, reflux condenser, additionfunnel and means for excluding moisture were placed a suspension of 3 glithium aluminum hydride in 30 ml diethyl ether. Then, while stirringthe flask contents and cooling the flask with an ice water bath tocontrol heat evolution, there were added over a period of 15 minutes asolution in 30 ml of 1,1,2-trichloro-2,2,1-trifluoroethane (Freon™113)of 15.75 g of a composition comprising polyfluoropolyether representedby Formula VIII where R¹ was --CF₃, R² was --CF₃, Q' was ##STR133##--CF₂ OCOF, and --CF₃, W' was a mixture of ##STR134## and --CF₂ OCOF,that had been prepared by heating overnight at 150° C. to removeperoxide linkages from the photooxidation product of a mixture ofhexafluoropropene and perfluoro(methyl vinyl) ether prepared asdescribed in Example 1.

After the addition was complete and the evolution of heat had subsided,the mixture was heated at reflux overnight. The mixture was then cooledand 30 ml of water were slowly added to quench the reaction.Precipitated salts were then dissolved by addition of 30 ml of 10%aqueous hydrochloric acid and the product of the reduction reaction wastaken up with 100 ml of Freon™113. The Freon™ phase was spearated anddried over anhydrous magnesium sulfate. After removal of Freon™, therewere obtained 12.6 g of slightly cloudy, colorless fluid that by ¹⁹ FNMR spectrometry had a molecular weight of about 2000. Proton NMRspectrometry indicated that the product comprised a mixture ofpolyfluoropolyether carbinols represented by Formula VII where R¹ was--CF₃, R² was --CF₃, R⁷ and Y were --CF₃, --CF₂ CF(CF₃)CF₃, --CF₂CH(CF₃)OH, --CF₂ CH₂ OH, and --CF(CF₃)CH₂ OH, the relative proportionsof the end groups being 55 mol % --CF₃, 41 mol % --CF₂ CH(CF₃)OH, --CF₂CH₂ OH, and --CF(CF₃)CH₂ OH, and 4 mol % --CF₂ CF(CF₃)CF₃, and q/r was0.28, (s+s')/(q+r) was 0.16, and s/s'was 0.27. By thin layerchromatography on silica, the presence of a small amount (20%) ofnon-functional (--CF₃ terminated) material was detected.

EXAMPLE 26

As in the procedure of Example 25, a reduction product comprisingpolyfluoropolyether carbinols was prepared by adding to 6 g of lithiumaluminum hydride in 50 ml of diethyl ether, a solution in 60 ml ofFreon™113 of 31.8 g of a perfluoropolyether product Formula VIII whereR¹ was --CF₃, R² was --C₄ F₉, Q' was --CF₃, and W' was ##STR135## or Q',that had been prepared by the photooxidation of a mixture ofhexafluoropropene and perfluoro(butyl vinyl) ether as described inExample 3 and heated for 18 hours at 350° C. to remove peroxide linkagesand form the ketone end group. There were obtained 29.7 g of a cloudy,colorless fluid that by ¹⁹ F NMR spectroscopy had a number averagemolecular weight of 4150. NMR spectroscopy was consistent with a productcomprising polyfluoropolyethers represented by Formula VII where R² was--C₄ F₉, F⁷ was --CF₃, and W was --CF₂ CH(CF₃)OH and --CF₃. In theproduct, q/r was 0.11, (s+s')/(q+r) was 0.09, and s/s' was believed tobe between about zero and 0.5. By ¹⁹ F NMR spectroscopy a ratio of 0.6part of terminal --OH to 1.0 part of terminal --OCF₃ was found.

EXAMPLE 27

Into a 100 ml flask equipped with a stirrer were placed 20 ml of Freon™and 9.1 g of a product comprising hydroxyl group- terminatedpolyfluoropolyethers having pendant perfluoromethoxy groups that wasprepared as described in Example 25. There were then added by syringe0.950 ml (0.690 g) triethylamine and 0.550 ml (0.620 g) acryloylchloride. A white precipitate began to form immediately. The mixture wasstirred overnight, then diluted with 100 ml of Freon™113 and washed in aseparatory funnel with 100 ml 5% aqueous hydrochloric acid. The aqueousphase was separated and extracted with 50 ml portions of Freon™113. Thecombined Freon™ phases were washed with 5% aqueous sodium hydroxide, theaqueous base phase extracted with Freon™113, and the conbined Freon™phases washed with aqueous sodium chloride and then placed over amixture of anhydrous magnesium sulfate and activated carbon for 24hours. The resulting solution was filtered and concentrated to give 7.95g of a cloudy fluid which was dissolved in 75 ml of Fluorinert®FC-75 (aperfluorinated solvent available from 3M Company), stored for 24 hoursover a mixture of anhydrous magnesium sulfate and activated charcoal,filtered, and concentrated under vacuum to yield 7.83 g of a clear fluidshown by proton NMR spectral analysis to be consistent with a productcomprising polyfluoropolyethers represented by Formula VII where R² was--CF₃, F⁷ was --CF₃, Y was ##STR136## and --CF₃ with the relativedistribution of the functional end groups, Y, being about 50 mol %##STR137## 25 mol % ##STR138## and 25 mol % ##STR139## In the product,q/r was 0.15, (s+s')/(q+r) was 0.07, s/s' was 0.27, and the numberaverage molecular weight was 2450.

When the procedure described above was repeated using a productcomprising hydroxyl-terminated polyfluoropolyethers having pendantperfluorobutoxy groups instead of the product comprisinghydroxyl-terminated polyfluoropolyethers having pendant perfluoromethoxygroups, there was obtained a clear fluid comprising polyfluoropolyethersrepresented by Formula VII where R⁷ was --CF₃, Y was a mixture of##STR140## and --CF₃ with the relative distribution of the functionalend groups Y being about 50 mol % ##STR141## 25 mol % ##STR142## and 25mol % ##STR143## and R² was --C₄ F₉. In the product, q/r was 0.17,(s+s')/(q+r) was 0.10, s/s' was believed to be between about zero and0.5, and the number average molecular weight was 2850.

EXAMPLE 28

Into a 50 ml flask equipped with stirrer, thermometer, reflux condenser,and means for maintaining the flask contents under inert gas were placed1.50 g of a hydroxyl group-terminated product that was prepared asdescribed in Example 25, 5 ml of Freon™113, 3 ml of glyme, and 0.01 g18-crown-6 phase transfer catalyst (available from Aldrich ChemicalCo.). A flow of argon gas was initiated and there were added 0.084 gfinely crushed potassium hydroxide and 0.30 g allyl benzene sulfonate.The mixture was heated to 45° C. and held at this temperature for 20hours during which time a white precipitate formed and after which time,thin layer chromatography indicated that the alcohol had reacted.Freon™113 and water were then added, the mixture shaken, and the phasesallowed to separate. The Freon™113 phase was separated and washed with10% aqueous sodium bicarbonate, washed with water, and allowed to dryover anhydrous magnesium sulfate for 24 hours. The mixture was filteredand the solvent removed by distillation to yield a cloudy fluid that wasclarified by dissolving in Fluorinert®FC-75, treating with activatedcarbon, filtering, and removing solvent. The product comprisedpolyfluoropolyethers represented by Formula VII where R⁷ was --CF₃, Ywas ##STR144## and --CF₃, with the relative proportion of the functionalend groups Y being about 50 mol % ##STR145## 25 mol % ##STR146## and 25mol % --CF₂ CH₂ OCH₂ CH═CH₂, and R² was --CF₃. In the product, q/r was0.28, (s+s')/q+r was 0.16, s/s' was 0.29, and the number averagemolecular weight was about 2200.

EXAMPLE 29

Into a 50 ml flask equipped with stirrer, thermometer, and means formaintaining the flask contents under inert gas were placed 1.2 g of ahydroxyl group-terminated product that was prepared as described inExample 25, 106 mg 2-isocyanatoethyl methacrylate and about 0.05 mldibutyl tin dilaurate. The mixture was heated to 40° C. and heldovernight at 30°-40° C. The clear product was dissolved inFluorinert®FC-75, treated with a mixture of activated carbon andanhydrous magnesium sulfate, filtered, and concentrated to give 1.13 gof a viscous fluid having infrared absorption for N--H of 3320 cm⁻¹,C--H of 2950 cm⁻¹, C═O of 1740 and 1710 cm⁻¹, and C═C of 1630 cm⁻¹.Proton NMR spectra showed the presence of a product comprisingpolyfluoropolyethers represented by Formula VII where R² was --CF₃, R⁷was --CF₃, Y was ##STR147## and --CF₃ with the relative distribution ofthe functional end groups Y being about 50 mol % ##STR148## In theproduct q/r was 0.28, (s+s')/(q+r) was 0.16, s/s' was 0.29, and thenumber average molecular weight was 2400.

EXAMPLE 30

A polyfluoropolyether carbinol product having pendant perfluorobutoxygroups was prepared following the procedure of Example 25 butsubstituting perfluoro(butyl vinyl) ether for the perfluoro(methylvinyl) ether. Into a vial equipped with a mechanical stirrer and meansfor excluding atmospheric moisture were placed 1.50 g of thepolyfluoropolyether carbinol product, 170 mg of 3-isocyanatopropyltriethoxysilane, and 1 drop dibutyl tin dilaurate as catalyst. Themixture was stirred overnight, after which time a single clear viscousphase had formed. The product was dissolved in Fluorinert®FC-75, treatedwith anhydrous magnesium sulfate and activated carbon, filtered, andconcentrated to give 1.1 g of clear vixcous fluid. Proton and ¹⁹ F NMRspectra were consistent with a product comprising polyfluoropolyethershaving pendant perfluorobutoxy groups and terminal triethoxysilyl groupsand represented by Formula VII where R² was --C₄ F₉, R⁷ was --CF₂CF(CF₃)₂ and --CF₃, Y was ##STR149## --CF₂ CF(CF₃)₂ and --CF₃. Therelative distribution of the end groups was 44 mol % ##STR150## 52 mol %--CF₃, 4 mol % --CF₂ CF(CF₃)₂, the distribution of functional end groupswas about 50 mol % ##STR151## 25 mol % ##STR152## and 25 mol %##STR153## In the product, q/r was 0.17, (s+s')/(q+r) was 0.10, s/s' wasbelieved to be between about zero and 0.5, and the number averagemolecular weight was 3000.

EXAMPLE 31

The procedure of Example 30 was repeated using, in place of3-isocyanatopropyl triethoxysilane, 0.32 g of 2,4-toluenediisocyanate.Proton NMR and infrared spectra on the clear colorless fluid obtainedwere consistent with a product comprising polyfluoropolyethers havingpendant perfluorobutoxy groups and terminal isocyanate groupsrepresented by Formula VII and similar to that of Example 30 except thatthe functional end groups Y were ##STR154## (The isomers being thosehaving the --CH₃ in positions 2, 4, and 6.)

EXAMPLE 32

Into a 3-neck round bottom flask equipped with a mechanical agitator, acondenser having circulating fluid at 0° C., and an addition funnel wereplaced 255 ml tetrahydrofuran, 5.13 g zinc chloride, and 2.67 g sodiumborohydride. The flask was purged for several minutes with nitrogen andthe flask heated by a fluid bath at 65° C. When reflux began, there wereadded a solution, in 90 ml of fluorinert®FC-75 solvent, of 59.4 g of apolyfluoropolyether dimethyl ester which by ¹⁹ F NMR spectral analysishad a number average molecular weight of 1760 and comprised thepolyfluoropolyether represented by Formula VI where R⁶ was --CF₂ COOCH₃and --CF₂ COOH, Y was --CF₂ COOCH₃, --CF₂ COOH, --C₂ F₄ Cl, --CF₂ Cl,and --CF₃, R' was fluorine, R² was --C₄ F₉, k/l was 1.64 and(p+p')/(k+l) was 0.0131. The relative proportions of the R⁶ and Y endgroups were 90 mol % --CF₂ COOCH₃, 6 mol % --CF₂ COOH, 1 mol % --CF₃, 2mol % --C₂ F₄ Cl and 1 mol % --CF₂ Cl. The mixture was left at refluxfor 16 hours. The mixture was allowed to cool to 25° C. and then 330 mlof 1N hydrochloric acid were added over a period of 30 minutes. Themixture was stirred for another 30 minutes, the fluorocarbon layerseparated and washed two times with an equal volume of deionized water.After stripping off the volatiles at 55° C. under 20 torr, there wereobtained 52.0 g of a product containing a polyfluoropolyether diolhaving an average structure of Formula VI where R¹ was fluorine, R² wasC₄ F₉, R⁶ was --CF₂ CH₂ OH, --CF₃, --CF₂ Cl, and --C₂ F₄ Cl, Y was --CF₂CH₂ OH, with relative proportions of end groups R⁶ and Y being 96 mol %--CF₂ CH₂ OH, 2 mol % --CF₂ Cl, and 2 mol % --C₂ F₄ Cl. In the product,k/1 was 1.62, (p+ p')/(k+1) was 0.0153 and the number average molecularweight was 1920.

EXAMPLE 33

This example demonstrates improved release properties towards siliconepressure sensitive adhesives obtained with two different coatingscomprising acrylate-functional polyfluoropolyether compositions of thisinvention ("PPE acrylates" II and III prepared as in Example 27) havingperfluoro(methyl vinyl) ether incorporated into the polyether chains,represented by Formula VII where R² was --CF₃, R⁷ was --CF₃, and Y was##STR155## and --CF₃. For comparison, a similar acrylate-functionalpolyfluoropolyether composition ("PPE acrylate" I) having no vinyl etherincorporated into the polyether chain was prepared. The number averagemolecular weight and the ratios q/r and (s+s')/(q+r) of the threeacrylate compositions are shown in Table I.

                  TABLE II                                                        ______________________________________                                        PPE acrylate                                                                             q/r       (s + s')/(q + r)                                                                           --Mn                                        ______________________________________                                        I          .04       0            2250                                        II         .15       .07          2450                                        III        .28       .16          2100                                        ______________________________________                                    

Each polyfluoropolyether acrylate was coated onto a polyester film froma 1 weight percent solution in FC-77 (a fluorochemical solvent availablefrom 3M Company) using a No. 3 wire-wound Mayer bar. Evaporation ofsolvent left dried polyfluoropolyether coatings with calculatedthickness of about 700 Å. The polyfluoropolyether coatings were passedunder a pair of medium pressure mercury lamps at about 120 watts per cmusing an ultraviolet processor from PPG Industries, Model QC 1202 AN3IR,with a web speed of 18.5 m/min and a nitrogen atmosphere.

The photocured release coatings were laminated with apoly(dimethylsiloxane) pressure sensitive adhesive tape (MacDermid P-3,0.05 mm adhesive thickness, available from MacDermid Company). Initialrelease peel force was measured for each laminate at a peel angle of180° and peel speed of 2.3 m/min using an Imass Slip/Peel Tester, modelSP-102B-3M90. After the release peel test, readhesion peel force onglass was measured for the silicone adhesive tape using the same peelconditions. A second set of laminates was aged at 70° C. for 3 daysbefore testing for release peel force and readhesion peel force in thesame manner. Peel test results are shown in Table III. The adhesion peelforce for the tape to glass without prior lamination to the releasecoating was 436 g/cm.

                  TABLE III                                                       ______________________________________                                        PEEL TEST RESULTS                                                                    Initial       Aged 3 days 70° C.                                         Release   Readhesion                                                                              Release Readhesion                               PPE acrylate                                                                           Peel Force                                                                              Peel Force                                                                              Peel Force                                                                            Peel Force                               Coating  (g/cm)    (g/cm)    (g/cm)  (g/cm)                                   ______________________________________                                        I        6.9       424       11.0    413                                      II       5.1       436       8.7     413                                      III      3.4       424       6.3     402                                      ______________________________________                                    

As can be seen from the results in Table III, the presence of theperfluoromethoxy groups resulting from the incorporated perfluoro(methylvinyl) ether provided a significant reduction in release peel force withlittle or no reduction in readhesion peel force.

EXAMPLE 34

The polyfluoropolyether acrylates I-III of Example 33 were also coatedonto polyester film which had been previously coated with a hydantoinhexacrylate (HHA) priming layer. The release coatings were prepared in amanner similar to Example 33 but using lower lamp power (80 watts/cm).The HHA primed film was prepared by coating a 5 weight percent solutionof hydantoin hexacrylate in methylethylketone containing 5 weightpercent 2,4-bis(trichloromethyl)-6-(3,4-dimethoxyphenyl)-3-triazine,based on the weight of the HHA, onto polyester film using a No. 3wired-wound Mayer bar. The dried HHA coatings were lightly cured using aPPG ultraviolet processor, model QC 1202 NA3IR, with 40 watts/cm lamppower, 50 m/min. web speed and air atmosphere. Release and readhesionpeel forces for laminates made with poly(dimethylsiloxane) pressuresensitive adhesive tape (MacDermid P-3) were measured in the same mannerdescribed in Example 33. These results are reported below in Table IV.The adhesion peel force for the tape to glass without prior laminationto the release coating was 435 g/cm.

                  TABLE IV                                                        ______________________________________                                               Initial       Aged 3 days 70° C.                                HHA Primed                                                                             Release   Readhesion                                                                              Release Readhesion                               PPE acrylate                                                                           Peel Force                                                                              Peel Force                                                                              Peel Force                                                                            Peel Force                               Coating  (g/cm)    (g/cm)    (g/cm)  (g/cm)                                   ______________________________________                                        I        23        424       18      413                                      II       18        435       13      402                                      III      12        424       10      402                                      ______________________________________                                    

As can be seen from the results in Table IV, the presence of theperfluoromethoxy groups resulting from the incorporated perfluoro(methylvinyl) ether provided a significant reduction in release peel force withlittle or no reduction in readhesion peel force.

EXAMPLE 35

This example demonstrates a release coating useful for solvent castperoxide-cured silicone pressure-sensitive adhesives comprisingpolyester film coated with acrylate functional polyfluoropolyetherrepresented by formula VII where R² was --CF₃, R⁷ was --CF₃, Y was##STR156## and --CF₃, q/r was 0.15, (s+s')/(q+r) was 0.07 and the numberaverage molecular weight was about 2450. The polyfluoropolyetheracrylate was coated onto a polyester film from a 0.75 weight percentsolution in Fluorinert®FC-77 (a fluorochemical solvent available from 3MCompany) using a No. 3 wire-wound Mayer bar. Evaporation of solvent leftdried polyfluoropolyether coatings with calculated thickness of about525 Å. The polyfluoropolyether coatings were passed under a pair ofmedium pressure mercury lamps at 120 watts/cm using an ultravioletprocessor from PPG Industries, Model QC 1201 AN3IR, with a web speed of18.5 m/min and a nitrogen atmosphere.

The photocured release coatings were solvent coated with two siliconepressure-sensitive adhesives (DC-280A, a poly(dimethyl siloxane)pressure-sensitive adhesive available from Dow-Corning Company andGE-518 Silgrip, a phenyl-containing polysiloxane pressure-sensitiveadhesive available from General Electric Company). Both adhesives werecoated from 33 weight percent solutions in xylene-toluene solvent alsocontaining 1.7 weight percent/weight adhesive Cadox TS-50 peroxidecatlayst (2,4-dichlorobenzoyl peroxide in silicone paste available fromNoury Chemical Corporation) using a knife coater with 0.3 mm orifice.The coatings were dried for 10 minutes at 70° C. leaving adhesivecoatings of approximately 0.05 mm thickness on the polyfluoropolyethercoatings. The adhesives were cured at 150° C. for 5 minutes and thecured coatings were laminated to 0.05 mm polyester film. The laminatedpolyester backing was used to measure the release peel force for peelingthe cured adhesives from the polyfluoropolyether coatings. Initialrelease peel force was measured at a peel angle of 180° and peel speedof 2.3 m/min using an Imass slip/peel tester, Model SP-102 B-3M90. Afterthe release peel test, readhesion peel force on glass was measured forthe silicone adhesives on the polyester backing using the same peelconditions. In the same manner, release peel force and readhesion peelforce were measured after aging the laminates at 70° C. for 3 days. Peeltest results are shown in Table V. For comparison, each adhesive wasapplied, as described above, to polyester film having nopolyfluoropolyether coating thereon to form pressure-sensitive adhesivetapes. Each tape was tested for adhesion to glass as described above.The adhesion of the DC-280A adhesive was 702 g/cm. The adhesion of theGE-518 adhesive was 619 g/cm.

                  TABLE V                                                         ______________________________________                                        Initial             Aged 3 days 70° C.                                        Release    Readhesion                                                                              Release  Readhesion                               Silicone                                                                             Peel Force Peel Force                                                                              Peel Force                                                                             Peel Force                               Adhesive                                                                             (g/cm)     (g/cm)    (g/cm)   (g/cm)                                   ______________________________________                                        DC-280A                                                                              25         740       26       761                                      GE-518 20         717       19       677                                      ______________________________________                                    

As can be seen from the data in Table V, the presence of theperfluoro(methyl vinyl) ether provided excellent release peel force withexcellent retention of adhesion peel force.

EXAMPLE 36 (Viscosity/Molecular Weight Relationships)

For a variety of polyfluoropolyether peroxide materials prepared byphotooxidation of tetrafluoroethylene both in the presence and absenceof pendant perfluoroalkoxy groups, number average molecular weights weremeasured using endgroup analysis obtained from ¹⁹ F NMR spectra. For thesame materials, absolute viscosities were measured at 25° C. using aBrookfield model RVTDCP cone-and-plate viscometer. These data and thestructural parameters for the materials are given in Tables VI and VII.

For the control materials not containing pendent perfluoroalkoxy groups,the viscosities and molecular weights (Table VI) can be correlated withthe equation

    n=KM.sup.a                                                 (1)

where n=absolute viscosity (cp) at 25° C., M=number average molecularweight, K=1.15×10¹⁰, a=3.07. The regression coefficient r² for thecorrelation is 0.97.

Table VII shows molecular weights, measured viscosities, and predictedviscosities from equation (1) for tetrafluoroethylene-basedpolyfluoropolyether peroxides containing pendant perfluoroalkoxy groups.The measured viscosities are significantly lower than would be predictedusing data for control materials, and the deviation from predictedviscosity increases with increasing concentrations of pendantperfluoroalkoxy groups (Table VII, entries 8, 9, and 11).

                  TABLE VI                                                        ______________________________________                                               Absolute                                                                      viscosity                                                                              Structural parameters.sup.1                                   Sample   n(cp, 25° C.)                                                                     MW.sub.n  b/c  e/b + c                                    ______________________________________                                        1        1163       15600     1.10 0.032                                      2        1828       21000     1.37 0.071                                      3        1891       22000     1.16 0.027                                      4        2314       22000     0.96 0.095                                      5        15380      39000     1.03 0.16                                       6        13900      42000     0.63 0.24                                       7        34563      48000     0.64 0.18                                       ______________________________________                                         .sup.1 See Formula III: d = 0, d' = O, R.sup.1 = F                       

                                      TABLE VII                                   __________________________________________________________________________    Absolute viscosity                                                                          Predicted viscosity                                                                      Structural parameters.sup.1                          Sample                                                                             n(cp, 25° C.)                                                                   (cp, 25° C.)                                                                      MW.sub.n                                                                           b/c (d + d')/(b + c + d + d')                                                                   e/(b + c + d                                                                             R.sup.2            __________________________________________________________________________     8    1718    2828       23000                                                                              1.27                                                                              0.034         0.052      CF.sub.3            9    999     3221       24000                                                                              1.37                                                                              0.064         0.055      CF.sub.3           10   27435    97971      73000                                                                              0.57                                                                              0.055         0.32       n-C.sub.4                                                                     F.sub.9            11   59415    723287     140000                                                                             0.52                                                                              0.10          0.31       n-C.sub.4                                                                     F.sub.9            __________________________________________________________________________     .sup.1 See Formula III: R.sup.1 = F; d/d'˜2                        

Various modifications and alterations of this invention will becomeapparent to those skilled in the art without departing from the scope ofthe invention.

What is claimed is:
 1. Perfluoropolyether compositions comprising (1)normally liquid peroxidic poly(perfluorooxyalkylene) compositionscomprising a mixture of peroxidic poly(perfluorooxyalkylene) compounds,each compound comprising a backbone of randomly distributed,perfluorooxyalkylene units represented by the formulas --CF₂ O--,##STR157## and --O--, which, when bonded to an --O-- of any of theperfluorooxyalkylene units, forms a peroxy group, --O--O--, whichimparts the peroxidic characteristics to the composition, andbackbone-pendant perfluoroalkoxy groups, the terminal ether oxygen atomsof which are bonded to carbon atoms of the ##STR158## backbone units;(2) derivatives of the poly(perfluorooxyalkylene) compositionscomprising a mixtures of non-peroxidic polyfluoropolyether compounds;and (3) derivatives of the non-peroxidic polyfluoropolyether compoundscomprising functional and non-functional polyfluoropolyether compounds.2. Compositions according to claim 1 wherein said backbone isrepresented by the formula ##STR159## where each R¹ is independently afluorine or a perfluoroalkyl group selected from linear, branched, andcyclic groups;each OR² is independently a perfluoroalkoxy group whereinR² is a perfluoroalkyl group or a perfluoroalkyl group substituted withone or more further ether oxygen atoms; w is a number representing theaverage number of --CF₂ O-- units randomly distributed within the chainand has a value of 1 or greater; x is a number representing the averagenumber of ##STR160## units randomly distributed within the chain and hasa value of 1 or greater; y and y' are each a number representing theaverage number of ##STR161## units; respectively, randomly distributedwithin the chain, the sum of y and y' having a value of 1 or greater,and the ratio y/y' being 0 to 5; z is a number representing the averagenumber of oxygen atoms, --O--, randomly distributed within the chainwhich when bonded to an --O-- of the --CF₂ O--, ##STR162## forms aperoxy group, --O--O--, and has a value of 0 or greater; the ratio w/xis 5 or less; the ratio (y+y')/(w+x) is 0.01 to 1.5; and the ratioz/(w+x+y+y') is 0 to
 1. 3. Poly(perfluorooxyalkylene) compositionsaccording to claim 2 wherein R² is independently selected from unitshaving the structure --R³ O--_(f) R⁴, in which each R³ is independentlyselected from --CF₂ --, --CF₂ CF₂ --, and ##STR163## and R⁴ is aperfluoroalkyl group selected from linear, branched, and cyclic groups,and f is zero or a number having a value of 1 to
 6. 4.Poly(perfluorooxyalkylene) compositions according to claim 2 wherein wis 1 to about 10,000; x is 1 to about 10,000, and the sum of y and y' is1 to about 800; and z is 0 to about
 5000. 5. Poly(perfluorooxyalkylene)compositions according to claim 2 wherein said ratio (y+y')/(w+x) is0.05 to 1.5.
 6. Poly(perfluorooxyalkylene) compositions according toclaim 2 wherein said compounds have a number average molecular weight ofabout 650 to 1,000,000.
 7. Polyfluoropolyether compositions according toclaim 1 comprising polyfluoropolyethers represented by the formula##STR164## where each R¹ is independently a fluorine or a perfluoroalkylgroup selected from linear, branched, and cyclic groups;each OR² isindependently a perfluoroalkoxy group wherein R² is a perfluoroalkylgroup or perfluoroalkyl group substituted with one or more further etheroxygen atoms, independently selected from units having the structure--R³ O--_(f) R⁴, in which each R³ is independently selected from --CF₂--, --CF₂ CF₂ -- and ##STR165## and R⁴ is a perfluoroalkyl groupselected from linear, branched, and cyclic groups, and f is zero or anumber having a value of 1 to 6; w is a number representing the averagenumber of --CF₂ O-- units randomly distributed within the chain and hasa value of 1 or greater; x is a number representing the average numberof ##STR166## units randomly distributed within the chain and has avalue of 1 or greater; y and y' are each a number representing theaverage number of ##STR167## units, respectively, randomly distributedwithn the chain, the sum of y and y' having a value of 1 or greater, andthe ratio y/y' being 0 to 5; z is a number representing the averagenumber of oxygen atoms, --O--, randomly distributed within the chainwhich when bonded to an --O-- of the --CF₂ O--, ##STR168## forms aperoxy group, and has a value of 0 or greater; the ratio w/x is 5 orless; the ratio (y+y')/(w+x) is 0.01 to 1.5; the ratio z/(w+x+y+y') is 0or 1; when z is zero, G and J are independently selected from --C_(j)F_(2j) X in which X is hydrogen or halogen and when X is hydrogen, thenj is 1 or 2, and when X is halogen, then j is a integer of 1 to 5, or Gand J are terminal functional groups which can enter into an addition orcondensation reaction to form a homopolymer or copolymer, and when z is1 or greater, and when z is zero, G is selected from --COF, --CF₂ COF,##STR169## --CF₂ COCF₃, --CF₂ C(OH)₂ CF₃, ##STR170## and --CF₂ COOH andJ is selected from --COF, --CF₂ COF, ##STR171## --CF₂ COCF₃, --CF₂C(OH)₂ CF₃, ##STR172## --CF₂ COOH, --C_(a) F_(2a+1) and --C_(a) F_(2a)Cl where a is an integer of 1 to 5; andthe number average molecularweight of the polyfluoropolyether is from about 650 to 1,000,000. 8.Peroxidic poly(perfluorooxyalkylene) compositions according to claim 1comprising peroxidic poly(perfluorooxyalkylenes) represented by theformula ##STR173## wherein Q is selected from --COF, --CF₂ COF, and--CF₂ COOH;W is a terminal group selected from Q and --C_(a) F_(2a+1)and --C_(a) F_(2a) Cl where a is an integer up to 5; each R¹ isindependently a fluorine or a perfluoroalkyl group selected from linear,branched, and cyclic groups; each OR² is independently a perfluoroalkoxygroup wherein R² is a perfluoroalkyl group or perfluoroalkyl groupsubstituted with one or more further ether oxygen atoms independentlyselected from units having the structure (R³ O)_(f) R⁴, in which each R³is independently selected from --CF₂ --, --CF₂ CF₂ -- and ##STR174## andR⁴ is a perfluoroalkyl group selected from linear, branched, and cyclicgroups, and f is zero or a number having a value of 1 to 6; and b is anumber representing the average number of --CF₂ O-- units randomlydistributed within the chain and has a value of 1 or greater; c is anumber representing the average number of ##STR175## units randomlydistributed within the chain and has a value of 1 or greater; d and d'are each a number representing the average number of ##STR176## units,respectively, randomly distributed within the chain, the sum of d and d'has a value of 1 or greater and the ratio d/d' is 0 to 5; e is a numberrepresenting the average number of --O-- units randomly distributedwithin the chain and has a value of 1 or greater; the ratio b/c is lessthan 5; the ratio (d+d')/(b+c) is 0.01 to 1.5; the ratio e/(b+c+d+d') is0.0001 to 1; and the number average molecular weight of thepoly(perfluorooxyalkylene) is from about 650 to 1,000,000. 9.Compositions comprising the mixtures of non-peroxidicpolyfluoropolyethers compounds according to claim 1, which compounds arerepresented by the formula ##STR177## wherein each Z is independently aterminal group which is a functional group Y which is or contains afunctional moiety which can enter into an addition or condensationreaction to form a polymer, or Z is a non-functional group --C_(j)F_(2j) X in which X is hydrogen or halogen and when X is hydrogen, thenj is 1 or 2, and when X is halogen, then j is an integer of from 1 to5;each R¹ is independently a fluorine or a perfluoroalkyl group selectedfrom linear, branched, and cyclic groups; each OR² is independently aperfluoroalkoxy group wherein R² is a perfluoroalkyl group orperfluoroalkyl group substituted with one or more further ether oxygenatoms, independently selected from units having the structure --R³O--_(f) R⁴, in which each R³ is independently selected from --CF₂ --,--CF₂ CF₂ -- and ##STR178## and R⁴ is a perfluoroalkyl group selectedfrom linear, branched, and cyclic groups, and f is zero or a numberhaving a value of 1 to 6, and g is a number representing the averagenumber of --CF₂ O-- units randomly distributed within the chain and hasa value of 1 or greater; h is a number representing the average numberof ##STR179## units randomly distributed within the chain and has avalue of 1 or greater; i and i' are each a number representing thenumber of ##STR180## units, respectively, distributed within the chain,the sum of i and i' has a value of 1 or greater and i/i' is 0 to 5; theratio g/h is less than 5; the ratio (i+i')/(g+h) is 0.01 to 1.5; andthenumber average molecular weight of the polyfluoropolyether is from about650 to 20,000.
 10. Non-functional polyfluoropolyether compoundsaccording to claim 1 comprising non-periodic polyfluoropolyethersrepresented by the formula ##STR181## each X is hydrogen or halogen andwhen X is hydrogen, then j is 1 or 2, and when X is halogen, then j isan integer of from 1 to 5;each R¹ is independently a fluorine or aperfluoroalkyl group selected from linear, branched, and cyclic groups;each OR² is independently a perfluoroalkoxy group wherein R² is asaturated perfluoroalkyl group or perfluoroalkyl group substituted withone or more further ether oxygen atoms, independently selected fromunits having the structure --R³ O--_(f) R⁴, in which each R³ isindependently selected from --CF₂ --, --CF₂ CF₂ -- and ##STR182## and R⁴is a perfluoroalkyl group selected from linear, branched, and cyclicgroups, and f is zero or a number having a value of 1 to 6, and g is anumber representing the average number of --CF₂ O-- units randomlydistributed within the chain and has a value of 1 or greater; h is anumber representing the average number of ##STR183## units randomlydistributed within the chain and has a value of 1 or greater; i and i'are each a number representing the average number of ##STR184## units,respectively, randomly distributed within the chain, the sum of i and i'has a value of 1 or greater and i/i' is 0 to 5; the ratio g/h is lessthan 5; the ratio (i+i')/(g+h) is 0.01 to 1.5; andthe number averagemolecular weight of the polyfluoropolyether is 650 to 20,000. 11.Functional polyfluoropolyether compounds according to claim 1 comprisingnon-peroxidic polyfluoropolyethers represented by the formula ##STR185##where Y is any terminal functional group which is or contains afunctional moiety which can enter into an addition or condensationreaction to form a homopolymer or copolymer;R⁶ is Y, a perfluoroalkylgroup, or a haloperfluoroalkyl group; each OR² is independently aperfluoroalkoxy group wherein R² is a perfluoroalkyl group orperfluoroalkyl group substituted with one or more further ether oxygenatoms, independently selected from units having the structure --R³O--_(f) R⁴, in which each R³ is independently selected from --CF₂ --,--CF₂ CF₂ -- and ##STR186## and R⁴ is a perfluoroalkyl group selectedfrom linear, branched, and cyclic groups, and f is zero or a numberhaving a value of 1 to 6; k is a number representing the average numberof --CF₂ O-- units randomly distributed within the chain and has a valueof 1 to 200; l is a number representing the average number of --CF₂ CF₂O-- units randomly distributed within the chain and has a value of 1 to200; p and p' are each a number representing the average number of##STR187## units, respectively, randomly distributed within the chain,the sum of p and p' has a value of 1 to 50, and p/p' is 0 to 5; theratio k/l is less than 5; the ratio (p+p')/(k+l) is 0.01 to 1.5; andthenumber average molecular weight of the polyfluoropolyether is from about650 to 20,000.
 12. The polyfluoropolyethers of claim 11 wherein R⁶ is Y.13. The polyfluoropolyethers of claim 11 wherein the functional moietyis selected from --OH, --SH, --NHR⁹, --COOR⁸, --SiR⁸.sub.α R¹⁰ ₃₋α,--CN, --NCO, ##STR188## --OSO₂ CF₃, --OCOCl, --OCN, --N(R⁸)CN,##STR189## --N═C, --I, --CHO, --CH(OCH₃)₂, --SO₂ Cl, --C(OCH₃)═NH, and--C(NH₂)═NH, wherein R⁸ is lower alkyl or phenyl, R⁹ is hydrogen or R⁸,R¹⁰ is a hydrolyzable group, α is an integer of 1 to 3, R¹¹ and R¹² areindependently hydrogen or lower alkyl of 1 to 4 carbon atoms or R¹¹ andR¹² together are alkylene and with carbons to which they are attachedform a carbocyclic ring of 5 to 6 carbon atoms.
 14. Thepolyfluoropolyethers of claim 13 wherein said functional moiety islinked to the ##STR190## by the linking group --CF₂ CH₂ --.
 15. Thepolyfluoropolyethers of claim 14 wherein said functional moiety isselected from ##STR191##
 16. The polyfluoropolyethers of claim 11wherein the functional moiety is selected from --OCH═CH₂, --NHCH₂ CH₂OH, --N(CH₂ CH₂ OH)₂, --OCH₂ CH═CH₂, --NHCH₂ CH═CH₂, --N(CH₂ CH═CH₂)₂,##STR192## --NH(CH₂)₃ Si(OCH₃)₃, and --OCH₂ CH(OH)CH₂ O(CH₂)₃ Si(OCH₃)₃and the functional group is linked to the ##STR193## by linking group##STR194##
 17. Functional polyfluoropolyether compounds according toclaim 1 comprising non-peroxidic polyfluoropolyethers represented by theformula ##STR195## wherein Y is a terminal functional group which is orcontains a functional moiety;R⁷ is a perfluoroalkyl group,haloperfluoroalkyl, or the terminal functional group Y; each OR² isindependently a perfluoroalkoxy group wherein R² is a saturatedperfluoroalkyl group or perfluoroalkyl group substituted with one ormore further ether oxygen atoms, independently selected from unitshaving the structure --R³ O--_(f) R⁴, in which each R³ is independentlyselected from --CF₂ --, --CF₂ CF₂ -- and ##STR196## and R⁴ is aperfluoroalkyl group selected from linear, branched, and cyclic grops,and f is zero or a number having a value of 1 to 6; q is a numberrepresenting the average number of --CF₂ O-- units randomly distributedwithin the chain and has a value of 1 up to about 50; r is a numberrepresenting the average number of ##STR197## units randomly distributedwithin the chain and has a value of 5 up to about 50; s and s' are eacha number representing the average number of ##STR198## units,respectively, randomly distributed within the chain, the sum of s and s'has a value of 1 up to about 50, and the ratio s/s' is 0 to 5; the ratioq/r is 0.01 to 1.0; the ratio (s+s')/(q+r) is 0.01 to 1.0; andthe numberaverage molecular weight of the polyfluoropolyether is from about 650 to10,000.
 18. The polyfluoropolyethers of claim 17 wherein R⁷ is aperfluoroalkyl group.
 19. The polyfluoropolyethers of claim 17 whereinR⁷ is selected from --CF₃, --CF₂ CF₃, and --CF₂ CF(CF₃)₂.
 20. Thepolyfluoropolyethers of claim 17 wherein the functional moiety isselected from --OH, --SH, --NHR⁹, --COOR⁸, --SiR⁸.sub.α R¹⁰ ₃₋α, --CN,--NCO, ##STR199## --OSO₂ CF₃, --OCOCl, --OCN, --N(R⁸)CN, ##STR200##--N═C, --I, --CHO, --CH(OCH₃)₂, --SO₂ Cl, --C(OCH₃)═NH, --C(NH₂)═NH, andthe like, wherein R⁸ is lower alkyl or phenyl, R⁹ is hydrogen or R⁸, R¹⁰is a hydrolyzable group α is an integer of 1 to 3, R¹¹ and R¹² areindependently hydrogen or lower alkyl of 1 to 4 carbon atoms or R¹¹ andR¹² together are alkylene and with carbons to which they are attachedform a carbocyclic ring of 5 to 6 carbon atoms.
 21. Thepolyfluoropolyethers of claim 17 wherein said functional moiety islinked to the ##STR201## by linking groups selected from --CF₂ CH₂ --,##STR202##
 22. The polyfluoropolyethers of claim 17 wherein said linkinggroup is --CF₂ CH₂ --, ##STR203## and the terminal functional moiety isselected from ##STR204##
 23. The composition of claim 11 wherein Y is--CF₂ COOCH₃ and R² is --CF₃, --C₂ F₅, C₃ F₇, or --C₄ F₉.
 24. Thecomposition of claim 11 wherein Y is --CF₂ CH₂ OH or 17 wherein Y is--CF₂ CH₂ OH, ##STR205## and R² is --CF₃, --C₂ F₅, --C₃ F₇, or C₄ F₉.25. The composition of claim 11 wherein Y is ##STR206## or 17 wherein Yis ##STR207## and R² is --CF₃, --C₂ F₅, --C₃ F₇, or --C₄ F₉.
 26. Thecomposition of claim 11 wherein Y is ##STR208## or 17 wherein Y is##STR209## and R² is --CF₃, --C₂ F₅, --C₃ F₇, or --C₄ F₉.
 27. Thefunctional polyfluoropolyether compounds according to claim 11 or 17wherein said functional moiety is hydroxyl, ester, acrylate,methacrylate, or substituted silane.
 28. A polymer having a backbonecomprising randomly distributed, perfluorooxyalkylene units representedby the formulas --CF₂ O--, ##STR210## and backbone-pendantperfluoroalkoxy groups, the terminal ether oxygen atoms of which arebonded to carbon atoms of the ##STR211## backbone units.
 29. A releaseagent comprising a polymerized, functional polyfluoropolyethercomposition of claim
 1. 30. The release agent of claim 29 wherein saidfunctional polyfluoropolyether composition comprises thepolyfluoropolyethers of claim 11 or 17.